Tuned radio frequency (rf) resonant materials and material configurations for sensing in a vehicle

ABSTRACT

This disclosure provides a tire formed of a body having multiple plies and a tread that surrounds the body. The plies and/or the treads and/or other surfaces of the tire include one or more resonators that respond to being interrogated by an externally generated excitation signal. Multiple resonators formed of electrically-conducting materials are disposed (e.g., printed) on the plies and/or tread and/or other surfaces of the tire. Each of a group of multiple resonators can be individually configured to respond to different frequencies of the excitation signal such that the presence of a response (e.g., a measured attenuation of the excitation signal return) or lack of response (e.g., based on comparison of the excitation signal return to calibration curves) from individual ones of the multiple resonators can be combined to form a serial number that is unique to the tire or other elastomer-containing component (e.g., belts, hoses, etc.) being interrogated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation-in-part of and claims thebenefit of priority to U.S. patent application Ser. No. 16/829,355,entitled “TIRES CONTAINING RESONATING CARBON-BASED MICROSTRUCTURES” andfiled on Mar. 25, 2020, which claims the benefit of priority to U.S.Provisional Patent Application No. 62/824,440, entitled “TUNING RESONANTMATERIALS FOR VEHICLE SENSING” and filed on Mar. 27, 2019, to U.S.Provisional Patent Application No. 62/979,215, entitled “WASTE ENERGYHARVESTING AND POWERING IN VEHICLES” and filed on Feb. 20, 2020, and toU.S. Provisional Patent Application No. 62/985,550, entitled “RESONANTSERIAL NUMBER IN VEHICLE TIRES” and filed on Mar. 5, 2020, and thispatent application claims the benefit of priority to U.S. ProvisionalPatent Application No. 63/008,262, entitled “RESONANCE SENSING IN TIRES”and filed on Apr. 10, 2020, and this patent application claims thebenefit of priority to U.S. Provisional Patent Application No.63/036,796, entitled “RESONANCE SENSING IN ELASTOMER-CONTAININGPRODUCTS” and filed on Jun. 9, 2020, all of which are assigned to theassignee hereof; the disclosures of all prior applications areconsidered part of and are incorporated by reference in this patentapplication.

TECHNICAL FIELD

This disclosure generally relates to sensors and, more specifically, tosplit ring resonators that can detect various properties of tires of avehicle.

DESCRIPTION OF RELATED ART

Advances in vehicle power types, including hybrid and electric-onlysystems, have created an opportunity for further technologicalintegration. This is true especially as modern vehicles transition intofully autonomous driving and navigation, where technology (as opposed totrained and capable humans) must routinely monitor vehicle componentperformance and reliability to ensure continued vehicle occupant safetyand comfort. Traditional systems, such as tire pressure monitoringsystems (TPMSs), may fail to provide the high degree of fidelityrequired for high-performance (such as racing) or fully autonomousdriving applications. Such applications can present unique challenges,such as rapid vehicle component (such as tire) wear encountered indemanding driving or racing or failing to have a human driver presentcapable of checking tire performance during vehicle operation.

SUMMARY

This Summary is provided to introduce in a simplified form a selectionof concepts that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tolimit the scope of the claimed subject matter. Moreover, the systems,methods and devices of this disclosure each have several innovativeaspects, no single one of which is solely responsible for the desirableattributes disclosed herein.

One innovative aspect of the subject matter described in this disclosurecan be implemented in a tire including a body formed of one or more tireplies. In some implementations, each tire ply may include a firstsplit-ring resonator (SRR) and a second SRR adjacent to the first SRR.The first SRR may include a plurality of first carbon particlesconfigured to uniquely attenuate an electromagnetic ping based at leastin part on a concentration level of the first carbon particles withinthe first SRR. The second SRR may include a plurality of second carbonparticles configured to uniquely attenuate the electromagnetic pingbased at least in part on a concentration level of the second carbonparticles within the second SRR. The first carbon particles may includefirst aggregates forming a first porous structure, and the second carbonparticles may include second aggregates forming a second porousstructure. In some instances, the first and second porous structuresinclude mesoscale structuring. In other instances, each of the first SRRand the second SRR includes one or more of electrically-conductingmaterials, metals, electrically-conducting non-metals, dielectricmaterials, or semiconducting materials.

In some implementations, an amount of the attenuation of theelectromagnetic ping by the first SRR and the second SRR may beindicative of an extent of wear of the tire ply. In otherimplementations, the first SRR may be configured to resonate at a firstfrequency in response to the electromagnetic ping, and the second SRRmay be configured to resonate at a second frequency in response to theelectromagnetic ping, the first frequency different than the secondfrequency. In some instances, the first and second frequencies form anencoded serial number. In some other instances, an amplitude of theresonance of the first SRR or the second SRR may be indicative of anextent of wear of the tire ply.

In some implementations, the first SRR and the second SRR may be printedonto a surface of the tire ply. In some instances, at least one of thefirst SRR or the second SRR has one of an oval shape, an ellipticalshape, a rectangular shape, a square shape, a circle shape, or a curvedline. In other instances, one or more of the first SRR or the second SRRis a cylindrical SRR. In some other instances, the first SRR and thesecond SRR may be configured as a pair of concentric rings. The firstSRR may be positioned outside the second SRR. In other implementations,the first SRR and the second SRR may be disposed within an inner linerof the tire. In some other implementations, the first SRR and the secondSRR may be disposed on a treaded side of the tire body.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the subject matter disclosed herein are illustratedby way of example and are not intended to be limited by the figures ofthe accompanying drawings. Like numbers reference like elementsthroughout the drawings and specification. Note that the relativedimensions of the following figures may not be drawn to scale.

FIG. 1A presents an in-situ vehicle control system including varioussensors formed of carbon-containing composites tuned to demonstratedesirable radio frequency (RF) signal resonance and response upon beingpinged, according to some implementations.

FIG. 1B illustrates a signal processing system that analyzes chirpsignals that are frequency-shifted and/or attenuated by sensors formedof carbon-containing tuned RF resonance materials, according to someimplementations.

FIG. 1C illustrates a signal processing system that analyzestemporally-changing telemetry signals generated by (or otherwiseassociated with) self-powered telemetry, the signals beingfrequency-shifted and/or attenuated by sensors formed ofcarbon-containing tuned RF resonance materials, according to someimplementations.

FIG. 2A depicts a sensing laminate including alternating layers ofcarbon-containing resin and carbon fiber in contact with one-another,according to some implementations.

FIG. 2B1 and FIG. 2B2 depict, respectively, two example configurationsof frequency-shifting phenomena as demonstrated by a sensing laminateincluding carbon-containing tuned RF resonance materials, according tosome implementations.

FIG. 2B3 is a graph depicting idealized changes in RF resonance as afunction of deflection, according to some implementations.

FIG. 2B4 is a graph depicting changes in RF resonance for 4-layer and5-layer laminates, according to some implementations.

FIG. 2C depicts surface sensor deployments in areas of a vehicle,according to some implementations.

FIG. 2D illustrates various electric current generation systems capableof integrating with the surface sensors deployments shown in FIG. 2C,according to some implementations.

FIG. 2E illustrates a table for various numerical values relating toenergy harvesting for vehicles, according to some implementations.

FIG. 2F illustrates a table for various properties relating to energyharvesting for vehicles, according to some implementations.

FIG. 2G illustrates a collection of common materials used in atriboelectric series organizes as dependent on polarity and/orpolarizability, according to some implementations.

FIG. 2H illustrates a signature classification system that processessignals received from sensors formed of tuned carbon-containing RFresonance materials, according to some implementations.

FIG. 3A depicts a prior art pressure-based battery-powered tirecondition sensor, such as that which may be a part of (or otherwiseassociated with) a tire pressure monitoring system (TPMS), according tosome implementations.

FIG. 3B depicts operation of a vehicle tire equipped with sensors havingtuned carbon-containing RF resonance materials embedded in tire plies,according to some implementations.

FIG. 3C depicts a series of tire condition parameters that are sensedfrom changes in RF resonance of various layers of carbon-containingtuned RF resonance materials, according to some implementations.

FIG. 3D depicts a manufacturing technique for tuning multiple plies of atire by selecting carbon-containing tuned RF resonance materials fromseparate and independent reactors for incorporation into the body of asingle tire assembly, according to some implementations.

FIG. 3E depicts a first set of example condition signatures that areemitted from tires formed of layers of tuned carbon-containing RFresonance materials, according to some implementations.

FIG. 3F1 depicts a second set of example condition signatures that areemitted from new tires formed of layers of carbon-containing tuned RFresonance materials, according to some implementations.

FIG. 3F2 depicts a third set of example condition signatures that areemitted from tires after wear-down of some of the carbon-containingtuned RF resonance materials, according to some implementations.

FIG. 3F3 depicts a graph of measured resonant signature signal intensity(in decibels, dB) against height (in millimeters, mm) of tire treadlayer loss, according to some implementations.

FIGS. 3G1 and 3G2 depict schematics of example conventional carbonmaterial production chains, according to some implementations.

FIG. 4A illustrates a schematic diagram representative of a flow (withinsemi-conducting materials) of charge carriers between hot and coldregions to create a voltage difference to allow thermo-electricgenerators (TEGs) to operate in low or no light conditions, according tosome implementations.

FIG. 4B illustrates carbon-based materials incorporated into plieswithin the body or treads of a tire tuned for electric conductivityand/or doped to produce power from waste heat, according to someimplementations.

FIG. 4C illustrates a chart for comparing output power against amagnitude of heat flux (delta of degrees Celsius) related tothermoelectric generation functionality integrated into tires, accordingto some implementations.

FIG. 5A illustrates a layered positive-negative (PN) junction typesemiconductor material incorporated into engine components for electricpower harvesting, according to some implementations.

FIG. 5B is a graph of conventional materials incorporated within rubberof a vehicle tire, comparing normalized capacitance (C/C0) againstrubber thickness (mm), according to some implementations.

FIG. 6A illustrates a schematic diagram showing a complete tirediagnostics system and apparatus for tire wear sensing throughimpedance-based spectroscopy, according to some implementations.

FIG. 6B illustrates tire information transferred via telemetry into anavigation system and equipment for manufacturing printed carbon-basedmaterials, according to some implementations.

FIG. 6C is a presentation of information related to the sensing of atire condition, according to some implementations.

FIG. 6D and FIG. 6E illustrate schematics, respectively, related to aresonant serial number-based digital encoding of vehicle tires throughtire tread layer and/or tire body ply-print encoding, according to someimplementations.

FIG. 7 illustrates a schematic diagram depicting various layers of tirebelt plies configured to generate electric power or current throughpiezo-electric capabilities, according to some implementations.

FIG. 8 illustrates a schematic cut-away diagram of a vehicle chassis,engine, and drivetrain to show powertrain losses (non-usable for forwardpropulsion power) associated with a conventional vehicle, according tosome implementations.

FIG. 9 illustrates a schematic cut-away diagram of a vehicle equippedwith piezoelectric and/or thermoelectric electric current and/or powergenerators, according to some implementations.

FIG. 10 illustrates various perspective schematic views of an advancedconceptual tire and various energy (current) delivery challenges,according to some implementations.

FIG. 11 is a side-view schematic diagram of a vehicle tire incorporatinggraphene-filled rubber and contacting a ground or pavement, according tosome implementations.

FIG. 12A through FIG. 12C illustrate schematic diagrams of chargegeneration on a rolling wheel (equipped with a single electrode and acopper-laminated polydimethylsiloxane, PDMS, patch, according to someimplementations).

FIG. 12D illustrates an example rotor and stator configuration of atriboelectric power generator or motor, according to someimplementations.

FIG. 13A illustrates schematic diagrams relating to various alternativetriboelectric power generators incorporated in vehicle tires and aconfiguration of an array of compressible hexagonal-structuredtriboelectric energy nanogenerators (CH-TENGs) fixed within a rubberpneumatic tire, according to some implementations.

FIG. 13B illustrates various types of triboelectric energy generatorconfigurations intended for incorporation within a vehicle tire,according to some implementations.

FIG. 14A is a schematic side-view of a substrate incorporating asubstrate electrode, according to some implementations.

FIG. 14B is a schematic view of a polyimide-based strain gauge tomonitor tire pressure, according to some implementations.

FIG. 14C is a schematic cut-away view of a hall sensor configured todetect vehicle tire tread deformation and incorporating gallium arsenide(GaAs) on ceramic, according to some implementations.

FIG. 14D through FIG. 14G show various schematic diagrams relating to anon-contact ultrasonic electric resistor-condenser parallel circuitintegrated on a steel wire belt of within the body of a tire, accordingto some implementations.

FIG. 15 through FIG. 17 depict structured carbons, various carbonnanoparticles, various carbon-based aggregates, and variousthree-dimensional carbon-containing assemblies that are grown over othermaterials, according to some implementations.

FIG. 18 illustrates a Raman shift plot for one or more of the structuredcarbons and/or the like shown in FIG. 15-17, according to someimplementations.

FIG. 19 illustrates a perspective view schematic diagram of an examplelattice-style arrangement of constituent elements (such as rubber) in atire tread layer and/or ply with resonant circuit components embeddedwithin or in-between the elements, according to some implementations.

FIG. 20 is an example Raman intensity heat map or plot representative ofsignal attenuation associated with the resonant circuit shown in FIG. 21when incorporated into a vehicle tire body ply and/or tread layer and inoperation, according to some implementations.

FIG. 21 is a schematic diagram showing an example configuration ofself-assembled carbon-based particles, according to someimplementations.

FIG. 22A through FIG. 22Y depict structured carbons, various carbonnanoparticles, various carbon-based aggregates, and variousthree-dimensional carbon-containing assemblies that are grown over othermaterials, according to some implementations.

FIG. 23 is presented to illustrate resonance mechanisms that contributeto the ensemble phenomenon arising from different proximally-presentresonant circuit types, according to some implementations.

FIG. 24 shows use of split ring resonant structures that are configuredto resonate in a manner that corresponds to an encoded serial number,according to some implementations.

FIG. 25 is a top view of two layers, where each layer hosts a split ringresonator, according to some implementations.

DETAILED DESCRIPTION

Various implementations of the subject matter disclosed herein relategenerally to deploying durable sensors comprising carbon-basedmicrostructures in vehicle components, such as within the plies of thebody of a conventional, currently commercially available pneumatic(referring to air, nitrogen or other gas-filled) tire, as well asnext-generation air-less solid tires. Configurations also exist wheresuch sensors with carbon-based microstructures can be (as an alternativeto tire ply implementations, or in addition thereto) incorporated withinportions of tire tread, referring to the rubber on its circumferencethat makes contact with the road or the ground. As tires are used, thetread is worn off, limiting its effectiveness in providing traction, andalso resulting in at least some of the carbon-containing sensorsdegrading and being worn off such that the absence of the sensors can bedetected by appropriately equipped componentry.

The referred-to carbon-based or carbon-containing microstructurematerials (available for implementation in either of the twoaforementioned discussed scenarios, including: (1) within the tire ply;and/or, (2) within the tire tread) can be tuned during in-flightsynthesis (such as within a chemical reactor or reaction vessel) toachieve specific expected radio frequency (RF) signal shift (referringto frequency shift) and signal attenuation (referring to thediminishment of signal magnitude) behavior relative to RF signalsemitted, such as by a transceiver mounted within one or wheel wells of avehicle equipped with the disclosed systems and/or by ainductor-capacitor (LC) circuit, also referred to (interchangeably) as atank circuit, LC circuit or resonator.

The disclosed configurations function independently of moving parts,such as those often required for conventional tire pressure monitoringsystems (TPMSs), thus are less susceptible to wear and tear resultant ofroutine road usage and may be configured to communicate or otherwiseelectronically cooperate with pre-existing vehicle electroniccomponents, such as those implemented in an automobile for detection andcommunication of tire-related wear. Target RF resonance frequency valuesof disclosed composite materials made from carbon microstructures can befurther tuned by control of mechanisms responsible for carbon-on-carbonsynthesis, also referred to as “growth”, within a reaction chamber or areactor. Disclosed carbon microstructures and other materials candemonstrate interaction to yield target performance characteristics andbehaviors suitable for similar or dissimilar end-use application areas,such as knobby, low-pressure off-road tires compared to race-track onlyslicks without tread.

OVERVIEW Introduction

Advances in materials science and engineering have enabled thefine-tuning, including at the molecular structure, of carbon-basedmicrostructural materials to resonate, demonstrate frequency shiftingbehaviors, and/or to attenuate (referring to, in physics and wirelesstelecommunications, extinction of a signal through the gradual loss offlux intensity through a medium) at specified radio frequencies (RF)(such as from 0.01 GHz to 100 GHz) that can be further refined to fitthe needs of various end-use application areas. Carbon-basedmicrostructures can be self-assembled or “grown” in a reactor from acarbon-containing gaseous species to generate ornate three-dimensionalhierarchical carbon-based structures, which can be embedded as sensorswithin one or more plies and/or tread of the body of a vehicle tire, orsome other intended vehicle-related surface, component, and/or part,etc.

Changes in the environment surrounding the vehicle equipped with thedisclosed materials and systems can affect the resonance, frequencyshifting, and/or signal attenuation behavior of the carbon-basedstructures such that even the most minute aberrations in vehicle tireperformance, longevity, likelihood of degradation at a high-wear area,and so on and so forth, can be detected and communicated to the driver,passenger, or vehicle occupants more generally for fully autonomous(driver-less) vehicles in real-time (referring to as such changesoccur). That is, signals may be attenuated to a certain extent by thecarbon-containing microstructures embedded at certain concentrationlevels within one or more plies and/or treads of the tire such that thepresence of that ply, or tread, layer can be accurately and repeatedlydetermined. Should a tread (and/or a layer within the tread) exposed tocontact with a road surface, such as pavement, be eventually worn awaydue to repeated contact with the pavement (as experienced duringdriving), then the response of that tread layer (as demonstrated byattenuation or lack thereof) to emitted signals can indicate thepresence or absence of that tread layer, as well as the degree of wear.Abrupt or gradual transitions in weather or other environmentalconditions can cause variations in the physical characteristics of thedisclosed tuned carbon-based microstructures, which is detectablethrough observing alterations in frequency shifting and/or attenuationbehavior.

Changes in RF range resonant frequencies of the materials (such as thoseon the surface of or embedded within one or more tread layers) can bedetected by stimulating the RF resonant material with a signal (having aknown frequency) further emitted by patterned resonant circuits(referred to herein as “resonators”, which can be 3D printed onto thetire body plies) in response to signal stimulation from a transceiver(potentially mounted within one or more wheel wells) to then observe afrequency shift of that emitted signal as caused by thecarbon-containing microstructures, or to observe the extent of signalattenuation (also as caused by the carbon-containing microstructures).Characteristics of the signal can be electronically observed andanalyzed to gauge current environmental conditions, as well as changesin weather conditions, such as heavy rain transitioning to sleet, makingroad surfaces slick and extremely dangerous. Also, implementationsoutside of vehicle tire plies are envisioned. For instance, as airpressure changes while flowing over sections of vehicle bodywork,including ground-effects such as splitters, canards, bumpers, sideskirts, rear wings, spoilers and/or the like while the vehicle ismoving, the air pressure can cause slight deformations (orrepositioning) of at least some sections of the vehicular bodywork,which can thus corresponding changes in the RF resonance of formativecarbon-based materials used to form the airfoil. Such changes in the RFresonant frequency (or frequencies) can be observed and compared toknown and discrete calibration points to determine, with a very highdegree of fidelity and accuracy (not otherwise achievable throughconventional techniques), the air pressure as measured at one or moredefined detection points on the vehicle's bodywork at a given moment intime.

Materials (including composite materials made up of multiple constituentsubstances or materials) can be tuned to accommodate the specificoperational needs of tires (on and off-road variants) implemented in avehicle. During operation of a vehicle, its tires often experienceextremes in terms of physical stress, strain and deformation, as well asvibration. Tires can be constructed to include a body with one or moreinternal layers (referred to as a “ply” or “plies”, surrounded by treadsprotruding from the body), both the tire plies and treads (inclusive ofone or more tread layers within each tread) being formed of materialsthat can be tuned to particular RF resonant frequencies. Conventionaluse of tires, such as that encountered during on-road driving for mostroad tires, or off-road (such as in mountainous or other uneven terrain)for off-road tires, can cause slight deformations of portions of thetire, which can cause a change in the RF resonant frequency (at the timeof detection of that material, such as by being ‘pinged’ by a RF signal)any given material used to form the tire. Such changes in the resonantfrequencies (as demonstrated by either frequency-shifting and/orattenuation of emitted signals) as associated with any one or more ofthe presently disclosed carbon-based microstructural materials can bedetected and later compared to known calibration points to definitivelydetermine conditions inside the tire, such as increased wear in certainregions, as well as environmental conditions (outside the tire)potentially affecting the tire.

Functionality

Regarding overall system operational functionality, methods,apparatuses, and materials are disclosed herein relating to an entiresystem for sensing changes to vehicle components. As outlined above,items are shown for constructing such a vehicle sensing system capableof both: (1) sensing changes (due to environmental exposure, forexample, or over-use); and, (2) reporting-out using, for example,surface-implanted carbon-based microstructural material sensors (as usedanywhere on the body of a vehicle) and/or embedded sensors (e.g., asused in tires).

Theoretical underpinnings are then presented on how even a minisculeamount of deflection (such as due to air pressure on a vehicle skin, ordue to any external application of forces in/on a tire) can be detectedby ‘pinging’ (referring to the emitting and later observation andanalysis of RF signals) for then processing the “signature” of a giventire ply and/or tread layer (or other so-equipped surface or region) asdemonstrated by, for example, frequency domain return. Variousmechanisms for calibrating an observed signal signature (in a testsetting) and processing a return signature (in an operational setting)are discussed.

Methods (and related apparatuses) for fabrication of a tire with passiveembedded sensors in the form of tuned carbon structures that interactwith the elastomer are also presented. The nature of a return signatureupon pinging an embedded tire sensor is discussed, as is the mechanismfor making a tire from multiple plies—each of which employs a differenttuned carbon having a different tuned microstructure. These carbon-basedmicrostructures can be in the micron-sized scale, or alternatively inany one or more of the nanometer, micro and even meso-particle sizes upto the millimeter (mm) level.

Further observations that can be exploited in tire (and potentiallyother areas as well) sensing are also explored, including: (1)self-powered signatures from resonance in the GHz and MHz range as madepossible by tribological power generators to generate electric currentupon, for example, rotation of a vehicle tire and its repeated frictionand/or contact with the pavement or ground. Such tribological componentscan be integrated or otherwise incorporated within multiple steel beltsin between elastomer layers in one or more vehicle tire plies.

Notably the tribological (referring to the study and application of theprinciples of friction, lubrication, and wear as related to thegeneration of energy to create usable electric current or power) effectis available for usage through, for example, a pattern for a conductivepath (that may be at least partially carbon-based) to accommodate chargemovement. Doing so leads to the creation of an electric charge generator(as provided by the discussed triboelectric componentry), to then directthat charge into an appropriately equipped resonator (also referred toas a resonant circuit, etc.), which has a tunable natural frequency whenit is discharging. This natural frequency, as used herein, is in the MHzrange (or lower). Accordingly, the resonator can be charged (and/orpowered) by the triboelectric generator for the resonator to resonate(and thus emit RF signals) and discharge. The resonator can beconfigured to accommodate repeated charge-discharge cycles and be in anyone or more of a variety of shapes and/or patterns, including ovals thathave an inherent resonant value or properties (based on its formativematerials and/or construction).

Changes in the shape or orientation of the resonator may result in acorresponding change of any associated resonation constants. As aresult, any change in tire physical properties due to deformation (suchas under static conditions like internal tire pressure, or under dynamicconditions such as those encountered while running over Bots Dots, canchange the shape or orientation of the resonator. Different patterns canbe used to respond with greater sensitivity to one type of deformationover another (such as referring to lateral deformation encountered whilemoving around a curve compared to vertical motion encountered whilerunning over gravel or a rough surface).

Individual components in an equipped vehicle can demonstrate one or moreunique “signatures” defined by the carbon-containing microstructuralmaterials, where such signatures result from exposure to RF signals inthe KHz (or lower) range. Disclosed configurations include where dynamicoperational properties can be sensed using an embedded sensor (such in atire body ply and/or tread layer). Nevertheless, placement of theaforementioned triboelectric charge generators in tire plies near thetread can allow for digital observations of oscillations as the tirerotates. Such oscillations are in the low hertz range and can be usedfor dynamic sensing like revolutions per minutes (RPM), as well asrelatively more static testing, such as sending indications fortreadwear.

Disclosed carbon-based microstructural materials can support wearindication by both: (1) an externally-originating ‘ping’ signal emissionand/or transmission for frequency-shift and/or signal attenuationdetection capabilities, such as those offered by a digital signalprocessing, DSP, computer chip and/or transducers placed within thewheel well, or even within the rim, of a wheel; as well as with (2) anintra-tire, self-powered, self-pinging capability facilitated bytribological power generators embedded within, for example, tire pliesto provide charge and/or electric power to resonators. Option (1) asindicated above can use an external transceiver (a semiconductor chip)for both stimulus and response; while, option (2) can take advantage oftuned intra-tire resonant circuits that are constantly resonating in amanner that can be picked up by an external receiver (such as asemiconductor chip again—but without necessarily the need forseparately-supplied transmission power).

Appropriately equipped and/or prepared receivers, transceivers and/orthe like can discriminate between the many different signatures to veryprecisely and accurately identify (pin-point) a particular type of wearobserved at a specific region, such as deterioration of theinterior-facing sidewall of the right front tire due to aggressivecornering on a racetrack featuring elevation changes, etc.).

Definitions and Use of Figures

Some of the terms used in this description are defined below for easyreference. The presented terms and their respective definitions are notrigidly restricted to these definitions—a term may be further defined bythe term's use within this disclosure. The term “exemplary” is usedherein to mean serving as an example, instance, or illustration, and notnecessarily to serve as a desirable model representing the best of itskind. Therefore, any aspect or design described herein as “exemplary” isnot necessarily to be construed as preferred or advantageous over otheraspects or designs. Rather, use of the word exemplary is intended topresent concepts in a concrete fashion. As used in this application andthe appended claims, the term “or” is intended to mean an inclusive “or”rather than an exclusive “or”. Unless specified otherwise, or is clearfrom the context, “X employs A or B” is intended to mean any of thenatural inclusive permutations. That is, if X employs A, X employs B, orX employs both A and B, then “X employs A or B” is satisfied under anyof the foregoing instances. As used herein, at least one of A or B meansat least one of A, or at least one of B, or at least one of both A andB. In other words, this phrase is disjunctive, meaning lackingconnection or expressing a choice between two mutually exclusivepossibilities, for example “or” in “she asked if he was going orstaying”. The articles “a” and “an” as used in this application and theappended claims should generally be construed to mean “one or more”unless specified otherwise or is clear from the context to be directedto a singular form.

Various implementations are described herein with reference to thefigures. It should be noted that the figures are not necessarily drawnto scale, and that elements of similar structures or functions aresometimes represented by like reference characters throughout thefigures. It should also be noted that the figures are only intended tofacilitate the description of the disclosed implementations—they are notrepresentative of an exhaustive treatment of all possibleimplementations, and they are not intended to impute any limitation asto the scope of the claims. In addition, an illustrated implementationneed not portray all aspects or advantages of usage in any particularenvironment. The disclosed implementations are not intended to belimiting of the claims.

System Structure

FIG. 1A shows a block diagram of a vehicle condition detection system1A00 (intended to be equipped onto the vehicle). The vehicle conditiondetection system 1A00 may include sensors, such as tuned RF resonancecomponents 108 composed of multiple carbon-based microstructuralmaterials, aggregates, agglomerations, and/or the like such as thosedisclosed by Stowell, et al., in U.S. patent application Ser. No.16/785,020 entitled “3D Self-Assembled Multi-Modal Carbon-BasedParticle” filed on Feb. 7, 2020 (referred to herein in the collective as“carbon-based microstructure”). The tuned RF resonance components 108can be incorporated into any one or more of airfoil sensors 104, glasssensors 1051, tire sensors 106, and transceiver antennas 102 on avehicle, such as a conventional driver-driven automobile or afully-autonomous transport pod or vehicle capable of operating to movevehicle occupants without a human driver.

The tuned RF resonance components 108 can be configured toelectronically and/or wirelessly communicate, such as by measurement ofsignal frequency shift or attenuation, with any one or more of atransceiver 114, a vehicle central processing unit 116, a vehicle sensordata receiving unit 118, a vehicle actuators control unit 120, andactuators 122 including doors, windows, locks 125, engine controls 126,navigation/heads-up displays 128, suspension control 129, and an airfoiltrim 130. The various tuned RF resonance components 108 can cause ashift in observed frequencies of emitted RF signals (referred to as a“frequency-shift”, implying any change in frequency) via emitted “chirp”signals 110 and/or “returned” chirp signals 112 with the transceiver114. Reference to a “returned” chirp signal of the chirp signal 1100 canrefer to the electronic observation or detection of frequency shift orattenuation of emitted chirp signals 110 relative to one or more of thetuned RF resonance components 108 integrated into any one or more of theairfoil sensors 104 and/or the like (rather than an actual reflection orreturn of a signal from a sensor). The chirp signals 110 and thereturned chirp signals 112 can be in communication with (and thereforealso assessed by) any one or more of the vehicle central processing unit116, the vehicle sensor data receiving unit 118, the vehicle actuatorscontrol unit 120, and/or the actuators 122. The vehicle conditiondetection system 1A00 can be implemented using any suitable combinationof software and hardware.

Any one or more of the depicted various sensors of the vehicle conditiondetection system 1A00 can be formed of carbon-based microstructurestuned to achieve a specific RF resonance behavior upon being “pinged”(referring to being hit or otherwise contacted by) emitted RF signals.The vehicle condition detection system 1A00 (or any aspect thereof) canbe configured to be implemented in any conceivable vehicle useapplication, area, or environment, such as during inclement weatherconditions including sleet, hail, snow, ice, frost, mud, sand, debris,uneven terrain, water and/or the like.

The tuned RF resonance components 108 can be disposed around and/or onthe vehicle (such as within the cabin, engine compartment, or the trunk,or on the body of the vehicle). As shown in FIG. 1A, the tuned RFresonance components can include airfoil sensors 104, glass sensors 105,tire sensors 106, and transceiver antennas 102, any one or more of whichcan be implemented in modern vehicles during their production, or(alternatively) retro-fitted to pre-existing vehicles, regardless oftheir age and/or condition. The tuned RF resonance components 108 can beformed, in part, using readily available materials such as fiberglass(such as, for airfoils) or rubber (such as, for tires) or glass (suchas, for windshields). These conventional materials can be combined withcarbon-based materials, growths, agglomerates, aggregates, sheets,particles and/or the like, such as those self-nucleated in-flight in areaction chamber or reactor from a carbon-containing gaseous species andformulated to: (1) improve the mechanical (such as tensile, compressive,shear, strain, deformation and/or the like) strength of a compositematerial in which they are incorporated; and/or, (2) to resonate at aparticular frequency or set of frequencies (within the range of 10 GHzto 100 GHz). Variables that dominate RF resonance properties andbehavior of a material can be controlled independently from thevariables responsible for control of material strength.

Radio Frequency (RF) based stimulation (such as that emitted by thetransceiver 114 or emitted by a resonator) can be used to emit RFsignals to the tuned RF resonance components 108, the actuators 122(and/or the like, such as sensors implemented in or on the tuned RFresonance components 108) to detect their respective resonance frequencyor frequencies, as well as frequency shifts and patterns observed in theattenuation of emitted signals (which may be affected by internal orexternal conditions). For example, if a tuned RF resonance component(such as the tire sensors 106) has been specially prepared (referred toas being “tuned”) to resonate at a frequency of approximately 3 GHz,then the tire sensors 106 can emit sympathetic resonance or sympatheticvibrations (referring to a harmonic phenomenon wherein a formerlypassive string or vibratory body responds to external vibrations towhich it has a harmonic likeness) when stimulated by a 3 GHz RF signal.

These sympathetic vibrations can occur at the stimulated frequency aswell in overtones or sidelobes deriving from the fundamental 3 GHz tone.If a tuned resonance component (of the tuned RF resonance components108) has been tuned to resonate at 2 GHz, then when the tuned resonancecomponent is stimulated by a 2 GHz RF signal, that tuned resonancecomponent will emit sympathetic vibrations as so described. Thesesympathetic vibrations will occur at the stimulated frequency as well asin overtones or sidelobes (in engineering, referring to local maxima ofthe far field radiation pattern of an antenna or other radiation source,that are not the main lobe) deriving from the fundamental 2 GHz tone.Many additional tuned resonance components can be situated proximally toan RF emitter. An RF emitter might be controlled to first emit a 2 GHzping, followed by a 3 GHz ping, followed by a 4 GHz ping, and so on.This succession of pings at different and increasing frequencies isreferred to as a “chirp”.

Adjacent tire plies (such as those in contact with each other) within atire body, such as that generally shown by FIGS. 3F1-3F2, can havevarying concentration levels or configurations of carbon-basedmicrostructures to define sensors incorporated within that (referring tothe respective) tire body ply and/or tread layer to resonate at varyingdistinct frequencies that are not harmonic with one-another. That is,non-harmonic plies can ensure a distinct and easily recognizabledetection of a particular tire body ply and/or tread layer (or othersurface or material) relative to others with minimal risk of confusiondue to signal interference caused by (or otherwise associated with)harmonics.

The transceiver 114 (and/or a resonator, not shown in FIG. 1A) can beconfigured to transmit chirp signals 110 to any one or more of the tunedRF resonance components 108 to digitally recognize frequency shiftand/or attenuation of the chirp signals 111 (referred to as the returnedsignals 112 in FIG. 1A) from any one or more of the tuned RF resonancecomponents 108. Such “returned” signals 108 can be processed intodigital information that can be electronically communicated to a vehiclecentral processing unit 116, that interacts with a vehicle sensor datareceiving unit 118 and/or a vehicle actuators control unit 120, whichsend further vehicle performance related signals based on sensor datareceived. The returned signals 112 ₀ can at least partially control theactuators 122. That is, the vehicle actuators control unit 120 cancontrol the actuators 122 to operate any one or more of the doors,windows, locks 124, the engine controls 126, the navigation/heads-updisplays 128, the suspension control 129, and/or the airfoil trim 130according to feedback received from the vehicle sensor data receivingunit 118 regarding vehicle component wear or degradation as indicated bythe tuned RF components in communication with the transceiver 114.

Detection of road debris and inclement weather conditions uponmonitoring behavior (such as frequency shift and/or attenuation) of thechirp signal 111 can, for example, result in the actuators 122triggering a corresponding change in the suspension control 129. Suchchanges can, for example, include softening suspension settings toaccommodate driving over the road debris, while later tighteningsuspension settings to accommodate enhanced vehicle responsiveness asmay be necessary to travel during heavy rain (and thus low traction)conditions. The variations of such control by the vehicle actuatorscontrol unit 120 are many, where any conceivable condition exterior tothe vehicle can be detected by the transceiver (as demonstrated byfrequency shifting and/or attenuation of the chirp signals 110 and/orthe returned signals 112).

Any of the tuned RF resonance components 108 forming the describedsensors can be tuned to resonate when stimulated at particularfrequencies, where a defined shift in frequency or frequencies (ascaused by the carbon-based microstructures) can form one or more signalsignatures indicative of the material, or condition of the material,into which the sensor is incorporated.

Time variance or deviation (TDEV) (referring to the time stability ofphase x versus observation interval τ of the measured clock source; thetime deviation thus forms a standard deviation type of measurement toindicate the time instability of the signal source) of frequency shiftsin the returned signals 112 (such as that shown in a signal signature)can correspond to time variant changes in the environment of the sensorand/or time variant changes in the sensor itself. Accordingly, signalprocessing systems (such as any one or more of the vehicle centralprocessing unit 116, the vehicle sensor data receiving unit 118, and/orthe vehicle actuators control unit 120, etc.) can be configured toanalyze signals (such as chirp signals 110 and returned signals 112)associated with the sensors according to TDEV principles. Results ofsuch analysis (such as a signature analysis) can be delivered to thevehicle central processing unit 116, which (in turn) can communicatecommands to the vehicle actuators control unit 120 for appropriateresponsive action. In some configurations such responsive action by theactuators 122 can involve at least some human driver input, while inother configurations the vehicle condition detection system 1A00 canfunction entirely in a self-contained manner allowing for a so-equippedvehicle to address component performance issues as they arise in anentirely driverless setting.

FIG. 1B shows a block diagram of a signal processing system 1B00, whichcan include surface sensors 160 and embedded sensors 170, any one ormore of which may electronically communicate with the other concerningenvironmental changes 150 for a so-equipped vehicle (referring to avehicle equipped with the surface sensors 160 and the embedded sensors170). The signal processing system 1B00 may also include a transceiver114, a signature analysis module 154, and a vehicle central processingunit 116, any one or more of which is in electronic communication withthe other.

The signal processing system 1B00 functions to analyze a signalsignature (defined by digitally observing frequency shifting and/orattenuation of any one or more of chirp signals 111 and/or chirp signals110 as indicated in corresponding “returned” signals 112) once sensorsformed of carbon-based microstructures have been stimulated. As a resultof stimulation with a chirp signal sensor that resonate at one of thechirp/ping frequencies “respond” by resonating at or near itscorresponding tuned frequency, shifting the emitted frequency, and/orattenuating the amplitude of the emitted signal. When an environmentalchange (such as that resulting in the wear of a tire body ply and/ortread layer) occurs while the chirp/ping is emitted, “returned” signalscan monitored for variations in modulation—either higher or lower thanthe tuned frequency. Accordingly, the transceiver 114 can be configuredto receive “returned” signals 112 that are representative of thesurfaces that they are pinged on or against, etc.

The foregoing chirp/ping signals can be emitted (such as by non-audibleRF signal, pulse, vibration and/or the like transmission) by thetransceiver 114. Also, the “return” signals can be received by the same(or different) transceiver 114. As shown, chirp signals can occur in arepeating sequence of chirps (such as, chirp signals 110). For example,a chirp signal sequence might be formed of a pattern comprising a 1 GHzping, followed by a 2 GHz ping, followed by a 3 GHz ping, and so on. Theentire chirp signal sequence can be repeated in its entiretycontinuously. There can be brief periods between each ping such that thereturned signals from the resonant materials (returned signals 112) canbe received immediately after the end of a ping. Alternatively, or inaddition, signals corresponding to ping stimulus and signals of theobserved “response” can occur concurrently and/or along the same generalpathway or route. The signature analysis module can employ digitalsignal processing techniques to distinguish signals of the observed“response” from the ping signals. In situations where the returnedresponse comprises energy across many different frequencies (such as,overtones, sidelobes, etc.), a notch filter can be used to filter thestimulus. Returned signals that are received by the transceiver can besent to the signature analysis module 154, which in turn can sendprocessed signals to vehicle central processing unit 116. The foregoingdiscussion of FIG. 1B includes discussion of sensors formed ofcarbon-containing tuned resonance materials and can also refer tosensing laminates as well.

FIG. 1C shows a block diagram of a signal processing system 1C00, whichis substantially similar to the signal processing system 1B00 shown inFIG. 1B, such that a redundant description of like features is omitted.Environmental changes 150, such as that referring to precipitation likerain, snow, hail, sleet and/or the like, can be indicated by surfacesensors 160 and/or embedded sensors 170. Unlike surface sensors 160,embedded sensors 170 (which can be embedded within materials such astire plies) can employ and/or be powered by self-powered telemetryincluding tribological energy generators (not shown in FIG. 1C) alsoincorporated within the material enclosed the respective sensor.Accordingly, the tribological energy generators can generate usableelectric current and/or power by harvesting static charge buildupbetween, for example, a rotating tire or wheel and the pavement itcontacts, to power a resonant circuit (to be described in further detailherein), which can then resonate to emit a RF signal at a knownfrequency. As a result, an externally-mounted transceiver unit (such asthat mounted within each wheel well of a vehicle) can emit RF signalswhich are further propagated by the resonant circuits that aretribologically-powered and embedded in the plies of a tire body in thisconfiguration. Frequency shifts and/or attenuation of the magnitude ofthe emitted signals are likewise received and analyzed, for example, bya signature analysis module 154 and/or a vehicle central processing unit166.

Self-powered telemetry (referring to collection of measurements or otherdata at remote or inaccessible points and their automatic transmissionto receiving equipment for monitoring) can be incorporated in vehicletires. Self-powering telemetry, as referred to herein, includesexploiting tribological charge generation inside a tire, storage of thatcharge, and later discharge of the stored charge to or through aresonant circuit, to make use of the “ringing” (referring to oscillationof the resonant circuit responsible for further emission of RF signals)that occurs during discharge of the resonant circuit (referring to anelectric circuit consisting of an inductor, represented by the letter L,and a capacitor, represented by the letter C, connected together, usedto generate RF signals at a particular frequency or frequencies).

Ping stimulus can be provided, generally, in one of two possibleconfigurations of the presently disclosed vehicle component weardetection systems, including:

-   -   Reliance on signals or ‘pings’ generated by a stimulus source,        such as a conventional transceiver, located outside the tire (or        other vehicle component intended for monitoring regarding wear        from ongoing use) such as being incorporated within each wheel        well of a so-equipped vehicle; or    -   Usage of an intra-tire (referring to also being embedded in the        tire plies, similar to the sensors having carbon-based        microstructures) tribological energy generation devices that        harvest energy resultant from otherwise wasted frictional energy        between the rotating wheel and/or tire and the ground or        pavement in contact therewith. Tribology, as commonly understood        and as referred to herein, implies the study of the science and        engineering of interacting surfaces in relative motion. Such        tribological energy generation devices can provide electrical        power to intra-tire resonance devices which in turn self-emit        tire property telemetry.

Either of the above-discussed two ‘ping’ stimulus generators orproviders can have complex resonance frequencies (CRf) componentsranging from approximately 10 to 99 GHz (due, for example, resonancefrequency of small dimensions of structures like graphene platelets) aswell as lower frequency resonance in Khz range due to the relativelymuch larger dimensions of the discussed intra-tire resonance. Generally,CRf can be equated to a function of elastomer component innate resonancefrequency, carbon component innate resonance frequency, ratio/ensembleof the constituent components, and the geometry of the intra-tireresonance device.

FIG. 2A shows a schematic side-view cutaway diagram of a sensinglaminate 2A00 (that can be representative of any sensor discussed withrelation to that shown in FIGS. 1A-1C) composed of multiple layersdisposed on each other, including (sequentially) a carbon-containingresin 204 ₂, a carbon fiber 202 ₂, a carbon-containing resin 204 ₁, anda carbon fiber 202 ₁. The term “resin” (in polymer chemistry andmaterials science), generally, refers to a solid or highly viscoussubstance of plant or synthetic origin that is typically convertibleinto polymers (a large molecule, or macromolecule, composed of manyrepeated subunits). Synthetic resins are industrially produced resins,typically viscous substances that convert into rigid polymers by theprocess of curing. In order to undergo curing, resins typically containreactive end groups, such as acrylates or epoxides. And, the term“carbon fiber”, are fibers about 5-10 micrometers (μm) in diameter andcomposed mostly of carbon atoms. Carbon fibers have several advantagesincluding high stiffness, high tensile strength, low weight, highchemical resistance, high temperature tolerance and low thermalexpansion.

Any one or more of the carbon-containing resin 204 ₂, the carbon fiber202 ₂, the carbon-containing resin 204 ₁, and the carbon fiber 202 ₁ canbe tuned to demonstrate or exhibit one or more specific resonancefrequencies upon being pinged by RF signals by incorporating specificconcentration levels of the any one or more of the aforementionedcarbon-containing microstructures. The sensing laminate can include anyconfiguration, orientation, order, or layering of any one or more of thecarbon-containing resin 204 ₂, the carbon fiber 202 ₂, thecarbon-containing resin 204 ₁, and the carbon fiber 202 ₁ and/or feweror additional layers comprising similar or dissimilar materials.Additional layers of resin can be layered interstitially betweenadditional layers of carbon fiber.

Each layer of carbon-containing resin can be formulated differently toresonate at a different expected or desired tuned frequency. Thephysical phenomenon of material resonation can be described with respectto a corresponding molecular composition. For example, a layer having afirst defined structure, such as a first molecular structure willresonate at a first frequency, whereas a layer having a second,different molecular structure can resonate at a second, differentfrequency

Material having a particular molecular structure and contained in alayer will resonate at a first tuned frequency when that layer is in alow energy state, and will resonate at a second different frequency whenthe material in the layer is in an induced higher-energy state. Forexample, material in a layer that exhibits a particular molecularstructure can be tuned to resonate at a 3 GHz when the layer is in anatural, undeformed, low energy state. In contrast, that same layer canresonate at 2.95 GHz when the layer is at least partially deformed fromits natural, undeformed, low energy state. As a result, this phenomenoncan be adjusted to accommodate the needs for detecting, with a highdegree of fidelity and accuracy, even the most minute aberration to, forexample, a tire surface contacting against a road surface such aspavement and experiencing enhanced wear at a certain localized region ofcontact. Race cars racing on demanding race circuits (referring tohighly technical, windy tracks featuring tight turns and rapidelevational changes) can benefit from such localized tire wear ordegradation information to make informed tire-replacement decisions,even in time-sensitive race-day conditions.

The frequency-shifting phenomenon referred to above (such astransitioning from resonating at a frequency of 3 GHz to 2.95 GHz) isshown and discussed with reference to FIGS. 2B1-2B2. FIG. 2B2 depicts afrequency-shifting phenomenon as exhibited in a sensing laminate thatincludes carbon-containing tuned resonance materials.

As generally understood, atoms emit electromagnetic radiation at anatural frequency for a given element. That is, an atom of a particularelement has a natural frequency that corresponds to characteristics ofthe atom. For example, when a Cesium atom is stimulated, a valenceelectron jumps from a lower energy state (such as, a ground state) to ahigher energy state (such as, an excited energy state). When theelectron returns to its lower energy state, it emits electromagneticradiation in the form of a photon. For Cesium, the photon emitted is inthe microwave frequency range; at 9.192631770 THz. Structures that arelarger than atoms, such as molecules formed of multiple atoms alsoresonate (such as by emitting electromagnetic radiation) at predictablefrequencies. For example, liquid water in bulk resonates at 109.6 THz.Water that is in tension (such as, at the surface of bulk, in variousstates of surface tension) resonates at 112.6 THz. Carbon atoms andcarbon structures also exhibit natural frequencies that are dependent onthe structure. For example, the natural resonant frequency of a carbonnanotube (CNT) is dependent on the tube diameter and length of the CNT.Growing a CNT under controlled conditions to control the tube diameterand length leads to controlling the structure's natural resonantfrequency. According, synthesizing or otherwise “growing” CNTs is oneway to tune to a desired resonant frequency.

Other structures formed of carbon can be formed under controlledconditions. Such structures include but are not limited to carbonnano-onions (CNOs), carbon lattices, graphene, carbon-containingaggregates or agglomerates, graphene-based, other carbon containingmaterials, engineered nanoscale structures, etc. and/or combinationsthereof, any one or of which being incorporated into sensors of vehiclecomponents according to the presently disclosed implementations. Suchstructures can be formed to resonate at a particular tuned frequencyand/or such structures can be modified in post-processing to obtain adesired characteristic or property. For example, a desired property suchas a high reinforcement value can be brought about by selection andratios of combinations of materials and/or by the addition of othermaterials. Moreover, co-location of multiples of such structuresintroduces further resonance effects. For example, two sheets ofgraphene may resonate between themselves at a frequency that isdependent on the length, width, spacing, shape of the spacing and/orother physical characteristics of the sheets and/or their juxtapositionto each other.

As is known in the art, materials have specific, measurablecharacteristics. This is true for naturally occurring materials as wellas for engineered carbon allotropes. Such engineered carbon allotropescan be tuned to exhibit physical characteristics. For example, carbonallotropes can be engineered to exhibit physical characteristicscorresponding to: (a) a particular configuration of constituent primaryparticles; (b) formation of aggregates; and, (c) formation ofagglomerates. Each of these physical characteristics influence theparticular resonant frequencies of materials formed using correspondingparticular carbon allotropes.

In addition to tuning a particular carbon-based structure for aparticular physical configuration that corresponds to a particularresonant frequency, carbon-containing compounds can be tuned to aparticular resonant frequency (or set of resonant frequencies). A set ofresonant frequencies is termed a resonance profile.

Forming Frequency-Tuned Materials

Carbon-containing materials (such as those including carbon-basedmicrostructures) tuned to demonstrate a specific resonance frequencyupon being pinged by a RF signal can be tuned to exhibit a particularresonance profile by tailoring specific compounds that make up thematerials to have particular electrical impedances. Different electricalimpedances in turn correspond to different frequency response profiles.

Impedance describes how difficult it is for an alternating (AC) currentto flow through an element. In the frequency domain, impedance is acomplex number having a real component and an imaginary component due tothe structures behaving as inductors. The imaginary component is aninductive reactance (the opposition of a circuit element to the flow ofcurrent due to that element's inductance or capacitance; largerreactance leads to smaller currents for the same voltage applied)component X_(L), which is based on the frequency ƒ and the inductance Lof a particular structure:

X _(L)=2 πƒL  (Eq. 1)

As the received frequency increases, the reactance also increases suchthat at a certain frequency threshold the measured intensity (amplitude)of the emitted signal can attenuate. Inductance L is affected by theelectrical impedance Z of a material, where Z is related to the materialproperties of permeability μ and permittivity ε by the relationship:

$\begin{matrix}{{Z = {\sqrt{\frac{\mu^{\prime} + {j\;\mu^{''}}}{ɛ^{\prime} + {j\; ɛ^{''}}}} = \sqrt{\frac{\mu_{0}}{ɛ_{0}}}}},} & \left( {{Eq}.\mspace{14mu} 2} \right)\end{matrix}$

Thus, tuning of material properties changes the electrical impedance Z,which affects the inductance L and consequently affects the reactanceX_(L).

Carbon-containing structures such as those disclosed by Anzelmo, et al.,in U.S. Pat. No. 10,428,197 entitled “Carbon and Elastomer Integration”issued on Oct. 1, 2019, incorporated herein by reference in its entiretywith different inductances can demonstrate different frequency responses(when used to create sensors for the aforementioned systems). That is, acarbon-containing structure with a high inductance L (being based onelectrical impedance Z) will reach a certain reactance at a lowerfrequency than another carbon-containing structure with a lowerinductance.

The material properties of permeability, permittivity and conductivitycan also be considered when formulating a compound to be tuned to aparticular electrical impedance. Still further, it is observed that afirst carbon-containing structure will resonate at a first frequency,whereas second carbon-containing structure will resonate at a secondfrequency when that structure is under tension-inducing conditions, suchas when the structure is slightly deformed (such as, thereby slightlychanging the physical characteristics of the structure).

FIG. 2B1 depicts a first carbon-containing structure that resonates at afirst frequency, which can be correlated to an equivalent electricalcircuit comprising a capacitor C₁ and an inductor L₁. The frequency f₁is given by the equation:

$\begin{matrix}{f_{1} = \frac{1}{2\pi\sqrt{L_{1}C_{1}}}} & \left( {{Eq}.\mspace{14mu} 3} \right)\end{matrix}$

FIG. 2B2 depicts a slight deformation of the same firstcarbon-containing structure of FIG. 2B1. The deformation causes a changeto the physical structure, which in turn changes the inductance and/orcapacitance of the structure. The changes can be correlated to anequivalent electrical circuit comprising a capacitor C₂ and an inductorL₂. The frequency f₂ is given by the equation:

$\begin{matrix}{f_{2} = \frac{1}{2\pi\sqrt{L_{2}C_{2}}}} & \left( {{Eq}.\mspace{14mu} 4} \right)\end{matrix}$

FIG. 2B3 is a graph 2B300 depicting idealized changes in measuredresonance as a function of deflection. As an option, one or morevariations of graph 2B300 or any aspect thereof may be implemented inthe context of the implementations described herein. The graph 2B300 (orany aspect thereof) may be implemented in any environment.

The implementation shown in FIG. 2B3 is merely one example. The showngraph depicts one aspect of deformation, specifically deflection. As amember or surface undergoes deformation by deflection (such as curving),the deformation can change the demonstrated resonance frequency of themember upon being pinged by a signal, such as an RF signal. The shape ofthe curve can depend on characteristics of the member, such as oncharacteristics of the laminate that forms the member or surface. Thecurve can be steep at small variations, whereas the curve flattens asthe deflection reaches a maximum. Moreover, the shape of the curvedepends in part on the number of layers of the laminate, the geometry ofthe carbon structures, how the carbon is bonded into the laminate, etc.

FIG. 2B4 is a graph 2B400 depicting changes in resonance for 4-layerlaminates 292 and for 5-layer laminates 294. As an option, one or morevariations of graph 2B400 or any aspect thereof can be implemented inthe materials and systems described herein. Materials such as thedescribed laminates can be deployed into many applications. Oneparticular application is for surface sensors, which can be deployedinto or on or over many locations throughout a vehicle. Some suchdeployments are shown and described as pertains to FIG. 2C.

FIG. 2C depicts example surface sensor deployments 2C00 in selectedlocations of a vehicle. The example surface sensor deployments 2C00 orany aspect thereof may be implemented in or on a vehicle exposed to anypossible exterior environmental condition, such as snow, sleet, hail,etc.

Tuned resonance sensing carbon-containing materials can be incorporatedinto or with automotive features, surfaces, and/or components in thecontext of durable sensors in various exterior surfaces of vehicles. Asshown, the vehicle is equipped with surface sensors on the front faring(such as, hood) of the vehicle, on support members of the vehicle, andon the roof of the vehicle. Each of the foregoing locations of thevehicle can be subjected to stresses and accompanying deformationsduring operation of the vehicle. As examples, the surface sensors on thefront faring will undergo air pressure changes when the vehicle is inoperation (such as, during forward motion). Under the forces of the airpressure, the material that composes the surface can deform slightlyand, in accordance with the phenomenon described as pertains to FIG. 2B1and FIG. 2B2, demonstrate a change in resonant frequency of the materialproportionate to the degree of change or deformation of the material.Such a change can be detected using the “ping” and observationtechniques described earlier.

Observed emitted signals can collectively define a signature for aparticular material or surface and can be further classified. Specificcharacteristics of the signal can be isolated for comparison andmeasurement to determine calibration points that correspond to thespecific isolated characteristics. Accordingly, aspects of theenvironment surrounding a vehicle can be accurately and reliablydetermined.

For example, if the deformation of the surface sensor results in afrequency shift from 3 GHz to 2.95 GHz, the difference can be mapped toa calibration curve, which in turn can yield a value for air pressure. Avehicle component such as a panel, roof, hood, trunk, or airfoilcomponent can provide a relatively large surface area. In such cases,transceiver antennas can be distributed on the observable side of thecomponent. Several transceiver antennas can be distributed into anarray, where each element of the array corresponds to a section of thelarge surface area. Each transceiver antenna can be installed on orwithin the wheel wells of the surface sensor deployments 2C00 as shownand be independently stimulated by pings/chirps. In some cases, eachelement of the array can be stimulated sequentially, whereas, in othercases, each element of the array is stimulated concurrently.Aerodynamics of the vehicle can be measured over large surface areas bysignal processing employed to distinguish signature returns fromproximal array elements.

Signature returns from a particular array element can be analyzed withrespect to other environmental conditions and/or other sensed data. Forexample, deflection of a particular portion of an airfoil componentmight be compared with deflection of a different portion of the airfoilcomponent, which in turn might be analyzed with respect to then-currenttemperatures, and/or then-current tire pressure, and/or any other sensedaspects of the vehicle or its environment.

FIG. 2D illustrates various electric current generation systems capableof integrating with the surface sensors deployments shown in FIG. 2C,according to some implementations. Any one or more of the shownelectrodynamic, photovoltaic, piezoelectric, and/or vibratory electriccurrent generation systems including regenerative braking systems 2D02,electrodynamic systems 2D18, photovoltaic systems 2D04, wind turbinesystems 2D06, photovoltaic and/or vibratory cells 2D08, piezoelectrictire pressure monitors 2D10, exhaust-based turbines 2D12,energy-harvesting shock absorbers 2D14 and/or supplementary powerdevices 2D16 can supplement triboelectric energy generators incorporatedwithin the plies of a tire body as discussed in FIG. 2C and elsewhere.

The regenerative braking systems 2D02 can absorb, retain, and transformcaptured heat energy generated upon compression of brake pads of shoesagainst rotating brake rotors to useful electric current to powerresonators. And, such power can be re-applied or otherwise re-used toprovide a torque boost to enhance immediate off-the-line accelerationfor conventional internal combustion engine powered, or battery-powered,vehicles. Incident light (from being parked in sunshine outside, forexample) can be harvested by the photovoltaic systems 2D04, while windturbine systems can 2D06 can further capture, retain, and reapplyenergy.

Likewise, incident vibratory energy (such as that due to a truck drivingby near a parked car so-equipped with the disclosed systems of FIG. 2D)can be captured by vibratory cells 2D08, and energy due to vibrationsencountered while driving over uneven road surfaces can be captured bythe piezoelectric tire pressure monitors 2D10. The exhaust-basedturbines 2D12 can capture and re-supply exhaust gases (like aturbocharger in an internal combustion engine) to generate usableelectric power. Energy-harvesting shock absorbers 2D14 can absorb impactto retain that mechanical energy and transform it to useful electriccurrent to supply the supplementary power devices 2D16 to extend theusable range of hybrid or electric-only vehicles. Potentialsupplementary power sources and systems are too numerous and widespreadto be listed specifically herein, thus those skilled in the art willappreciate that the disclosed systems (and tribological energygenerators) can function with any available power capture and re-usesystem.

Functionality related to energy recycling can be incorporated indifferent classes of vehicles. Energy sources can be provided as afunction of required electric power magnitude, such as where vibratoryenergy-capture devices can retain approximately 800 μW per cm³ machineinduced vibration. Alternatively, or in addition, approximately 800 μWper cm³ can be captured from humans acting as charge-carrying devices(such as capacitors). Light (photovoltaic) and heat (thermoelectric)energy capture and recycle devices suitable for incorporation with anyof the disclosed systems can retain and re-use approximately 0.1-100mW/cm² (for photovoltaic devices) and 60 μW/cm² at a temperaturegradient of approximately 5° C. Ambient electromagnetic (EM) radiationradio frequency (RF) can impart approximately 0.26 μW/cm² at 1 V/m fieldstrength, and so on and so forth.

FIG. 2E illustrates a table 2E00 for various numerical values relatingto energy harvesting for vehicles. Possible scenarios relating to theincrease in energy harvesting are shown regarding the number of electricvehicles (EVs) sold (such as heavy industrial, etc.) and the percentageusing energy harvesting to charge traction batteries in, for example,year 2011 compared to (projected) year 2021.

FIG. 2F illustrates a table 2F00 for various properties relating toenergy harvesting for vehicles. Examples of energy harvestingtechnologies and their applicability to electric vehicles, land, waterand air are shown for each of the following electric power ranges: (1)microwatts to milliwatts; (2) milliwatts to watts; and, (3) watts totens of kilowatts, all per vehicle. Aforementioned power regenerationsystems are organized by potential power regeneration and deliverycapabilities (such as microwatts to milliwatts and increasing).

FIG. 2G illustrates a collection 2G00 of common materials used in atriboelectric series organizes as dependent on polarity and/orpolarizability, according to some implementations. Example materialsnoted for demonstrated positive polarity and/or polarizability includepolyformaldehyde 1.3-1.4, etc., whereas example materials noted fordemonstrated negative polarity and/or polarizability includepolytetrafluoroethylene (Teflon), etc. Those skilled in the art willappreciate that other possible example materials may exist regardingtriboelectric energy generation potential without departing from thescope and spirit of that shown in FIG. 2G and elsewhere.

FIG. 2H illustrates a signature classification system 2H00 thatprocesses signals received from sensors formed of carbon-containingtuned resonance materials. The signature classification system 2H00 canbe implemented in any physical environment or weather condition. FIG. 2Hrelates to incorporating tuned resonance sensing materials intoautomotive components for classifying signals (such as, signatures)detected by, classified and/or received from sensors installed invehicles. A ping signal of a selected ping frequency is transmitted atoperation 270. The ping signal generation mechanism and the pingtransmission mechanism can be performed by any known techniques. Forexample, a transmitter module can generate a selected frequency of 3GHz, and radiate that signal using an antenna or multiple antennae. Thedesign and location of the tuned antenna (such as mounted on and/orwithin any one or more of the wheel wells or a vehicle) can correspondto any tuned antenna geometry, material and/or location such that thestrength of the ping is sufficient to induce (RF) resonance in proximatesensors. Several tuned antennae are disposed upon or within structuralmembers that are in proximity to corresponding sensors. As such, when aproximal surface sensor is stimulated by a ping, it resonates back witha signature. That signature can be received (operation 274) and storedin a dataset comprising received signatures 276. A sequence oftransmission of a ping, followed by reception of a signature, can berepeated in a loop.

The ping frequency can be changed (operation 272) in iterative passesthrough the loop. Accordingly, as operation 274 is performed in theloop, operation 274 can store signatures 278, including a firstsignature 278 ₁, a second signature 2782 ₁ up to an Nth signature 278_(N). The number of iterations can be controlled by decision 280. Whenthe “No” branch of decision 280 is taken (such as, when there are nofurther additional pings to transmit), then the received signatures canbe provided (operation 282) to a digital signal processing module (suchas, an instance of signature analysis module 154 shown in FIG. 1B). Thedigital signal processing module classifies the signatures (operation284) against a set of calibration points 286. The calibrations pointscan be configured to correspond to particular ping frequencies. Forexample, calibration points 288 can include a first calibration point288 ₁ that can correspond to a first ping and first returned signaturenear 3 GHz, a second calibration point 288 ₂ that can correspond to asecond ping and second returned signature near 2 GHz, and so on for anyinteger value “N” calibration points.

At operation 290, classified signals are sent to a vehicle centralprocessing unit (such as, the vehicle central processing unit 116 ofFIG. 1B). The classified signals can be relayed by the vehicle centralprocessing unit to an upstream repository that hosts a computerizeddatabase configured to host and/or run machine learning algorithms.Accordingly, a vast amount of stimulus related to signals, classifiedsignals, and signal responses can be captured for subsequent dataaggregation and processing. The database can be computationallyprepared, referring to as being “trained”, provided a given set ofsensed measurements that can be correlated to conditions or diagnosesrelated to vehicular performance, such as tire degradation due torepeated use. Should, during the operation of the vehicle, the measureddeflection (such as, air pressure) of a particular portion of an airfoilcomponent differ from the measured deflection (such as, air pressure) ofa different portion of the airfoil component, a potential diagnosis maybe that one tire is underinflated and therefore causing vehicle rideheight to be non-uniform, resulting in airflow over, on, and/or aroundthe vehicle to demonstrate proportionate non-uniformities, as detectedby deflection on the airfoil component. Other potential conditions ordiagnoses can be determined by the machine learning system as well. Theconditions and/or diagnoses and/or supporting data can be returned tothe vehicle to complete a feedback loop. Instrumentation in the vehicleprovides visualizations that can be acted upon (such as, by a driver orby an engineer).

FIG. 3A depicts a (prior art) battery-powered tire condition sensor3A00. As shown, the prior art technique can rely on battery-poweredelectronics (such as, a pressure sensor 302, a battery 304, and anantenna 306), any one or more of which are located inside the inflatedtire to send signals to a receiver outside the inflated tire. This canencounter various challenges, including: (1) the battery-poweredelectronics may not survive in punishing environments (exterior to thevehicle); and, (2) the battery-powered electronics are inaccessibleduring the lifetime of the inflated tire.

A superior technique can involve the embedding of passive (referring togenerally non-battery powered) sensors or sensing materials into thetire material itself (such as on, in-between, or within individual tireplies, or the tire carcass, etc.). Mechanisms for tire sensing,including inside the tire sensing as well as outside the tireenvironmental sensing, are shown and described in further detail asfollows.

FIG. 3B depicts operation of tire condition sensors 3B00 embedded intires as (or at least partially within) one or more discrete (butinterconnected or contacting) layers of carbon-containing tunedresonance materials. Tire condition sensors 3B00 may be implemented inany environment. No battery-powered electronics are installed inside thetire, rather the one or more various tire tread layers and/or tire bodyplies of the tire can be composed of (and/or otherwise include sensorsmade from) carbon-containing tuned resonance materials, each of whichprepared to resonate at an ascertainable frequency distinct from theother tread layer and/or ply.

FIG. 3C illustrates various physical characteristics or aspects (tirecondition parameters 3C00) pertaining to incorporating tuned resonancesensing materials into automotive components (such as tires). Here, thefigure is presented with respect to addressing deployment of survivablesensors in tires, including non-pneumatic tires as well as pneumatictires. The construction of the tires may correspond to radial tires,bias ply tires, tubeless tires, solid tires, run-flat tires, etc. Tiresmay be used in any sorts of vehicles and/or equipment and/or accessoriespertaining to vehicles. Such vehicles may include aircraft, all-terrainvehicles, automobiles, construction equipment, dump trucks, earthmovers,farm equipment, forklifts, golf carts, harvesters, lift trucks, mopeds,motorcycles, off-road vehicles, racing vehicles, riding lawn mowers,tractors, trailers, trucks, wheelchairs, etc. The tires may, in additionor alternative to that presented, be used in non-motorized vehicles,equipment and accessories such as bicycles, tricycles, unicycles,lawnmowers, wheelchairs, carts, etc.

The parameters shown in FIG. 3C are as an example, and other variantsmay exist or otherwise be prepared to target specific desirableperformance characteristics of many conceivable end-use scenarios,including truck tires designed to offer increased longevity (at thepotential expense of road adhesion), or soft racing tires designed toprovide maximum road adhesion (at the potential expense of lifespan).

Various carbon structures are used in different formulations with othernon-carbon materials integrated into tires, which then undergomechanical analysis to determine their respective characteristics of thetires. Some of these characteristics can be determined empirically bydirect testing, while other characteristics are determined based onmeasurements and data extrapolation. For example, rolling uniformity canbe determined by sensing changes in force when the tire is subjected torolling over a uniform surface such as a roller, whereas tread life isbased on an abrasion test over a short period, the results of whichshort term test are extrapolated to yield a predicted tread life value.

More tire characteristics can be measured, but some of these measurementtechniques can be physically destructive to the tire, and thus measuredat a desired point in the life of the tire. In contrast, usingsurvivable sensors embedded in tires allows for such otherwisedestructive measurements to be made throughout the entire lifetime ofthe tire. For example, detection of response signals based on RF signalspinged against sensors e embedded in tires can be used for such sensing.Moreover, each body ply and/or tread layer of a tire can, as discuss,include durable (also referred to as “survivable”) sensors that aretuned to resonate at a particular frequency.

Ply used in a tire can be formulated to combine carbon-containingstructures with other materials to achieve a particular materialcomposition that exhibits desired performance (such as handling andlongevity) characteristics. The natural resonance frequency (orfrequencies) of the particular material composition can be subjected tospectral analysis to develop a spectral profile for the particularmaterial composition. This spectral profile can be used as a calibrationbaseline for that material. When the body ply and/or tread layer of thetire undergoes deformation, the spectral profile changes, which spectralprofile changes can be used as additional calibration points. Many suchcalibration points can be generated by testing, and such calibrationpoints can in turn be used to gauge deformation.

Analysis of the spectral response results in quantitative measurementsof many tire parameters. The tire parameters that can be determined fromsignature analysis, for example, can include tread life 322, handling ata first temperature 328, handling at a second temperature 326, rollingeconomy at a first temperature 330, rolling economy at a secondtemperature 332, rolling uniformity 336, and braking uniformity 338.

Responses, such as those spectrally represented based on return pingsignals received from sensors embedded in materials in tire ply, can berepresentative of the deformation observed. That is, a certain type oftire deformation will correspond with a certain type of specificresponse, such that a mapping between responses or response types can bedone to degradation types. Moreover, time-variant changes in thespectral response of a tire as it undergoes in-situ deformation can beused to determine many ambient conditions, some of which ambientconditions are discussed as pertains to FIG. 3E. In tires that areconstructed using multiple ply, each body ply and/or tread layer can beformulated to exhibit a particular tuned frequency or range offrequencies. For example, FIG. 3D shows a schematic diagram forconstructing a tire from multiple ply, each of which has as different aparticular tuned frequency or range of frequencies.

FIG. 3D depicts a schematic diagram 3D00 for fine-adjustment, or tuning,of multiple body plies and/or tread layers of a tire by selectingcarbon-containing tuned resonance materials for incorporation into atire assembly or structure, which can be implemented in any environment.FIG. 3D illustrates how to mix different carbons into tire compositeformulations that are in turn assembled into a multi-ply tire. Theresulting multi-ply tire exhibits the various resonance-sensitive andfrequency-shifting characteristics.

Multiple reactors (such as, reactor 352 ₁, reactor 352 ₂, reactor 352 ₃,and reactor 352 ₄) each produce (or otherwise transport or provide) aparticular carbon additive/filler to the network that is tuned to yielda particular defined spectral profile. The carbon additives (such as,first tuned carbons 354, second tuned carbons 356, third tuned carbons358, and fourth tuned carbons 360) can mixed with other (carbon-based ornon-carbon based) compositions 350. Any known techniques can be used tomix, heat, pre-process, post-process or otherwise combine the particularcarbon additives with the other compositions. Mixers (such as, mixer 362₁, mixer 362 ₂, mixer 362 ₃, and mixer 362 ₄) are presented to show howdifferent tuned carbons can be introduced into various components of atire. Other techniques for tire assembly may involve other constructiontechniques and/or other components that comprise the tire. Any knowntechniques for multi-ply tires can be used. Moreover, the spectralprofile of a particular body ply and/or tread layer (such as a group ofbody plies and/or tread layers 368, including a body ply and/or treadlayer 368 ₁, a body ply and/or tread layer 368 ₂, a body ply and/ortread layer 368 ₃, and a body ply and/or tread layer 368 ₄) can bedetermined based on the characterization of a particular body ply and/ortread layer formulation. For example, based on a stimulus and responsecharacterization, a first body ply and/or tread layer formulation (suchas, body ply and/or tread layer formulation 364 ₁) might exhibit a firstspectral profile, whereas a second body ply and/or tread layerformulation (such as, body ply and/or tread layer formulation 364 ₂)might exhibit a second spectral profile.

The resulting different formulations (such as, body ply and/or treadlayer formulation 364 ₁, body ply and/or tread layer formulation 364 ₂,body ply and/or tread layer formulation 364 ₃, and body ply and/or treadlayer formulation 364 ₄), each of which body ply and/or tread layerexhibits a corresponding spectra profile, are used in the different bodyply and/or tread layer that are formed into a tire assembly 366.

FIG. 3E depicts a first set of example condition signatures 3E00 thatare emitted from tires (exposed to any environment) formed of layers ofcarbon-containing tuned resonance materials. Several dynamic mechanicalanalysis tire parameters are shown that can be gauged based onoperation. A given tire or tires can be installed on one or more wheelsof a vehicle, then driven on by the vehicle in any environment. When thetire undergoes RF signal stimulation while also concurrently deformingdue to use (such as, deformation of one or more body ply and/or treadlayer of the tire), carbon-containing tuned resonance materials thatform sensor layers within the tire can emit a signature in response tothe stimulation which can be representative of the tire'scontemporaneous deformation.

The figure depicts merely some examples of deformations of one or morebody ply and/or tread layer of the tire as it is operated under variousconditions. Operation of the tire under various conditions result indifferent sets of signals (such as, condition-specific signals 345)being emitted by the various body ply and/or tread layer of the tire inresponse to stimulation while such conditions are present. As shown, thetire can be operated in warm ambient conditions, during which operationthe signals being emitted by the various body ply and/or tread layer ofthe tire in response to the stimulation are regarded as warm ambientsignals 340. Also as shown, the tire can be operated in cold ambientconditions, during which operation the signals being emitted by thevarious body ply and/or tread layer of the tire in response to thestimulation are regarded as cold ambient signals 342. Furthermore, thetire can be operated under conditions of low tire inflation, duringwhich operation the signals being emitted by the various body ply and/ortread layer of the tire in response to stimulation are regarded as lowtire pressure signals 344.

Signal processing, (such as, such as may be carried out by an instanceof the aforementioned signature analysis module 154 of FIG. 1B)classifies the condition-specific signals 345 against a set ofcalibration points that correspond to various environmental conditions.The calibrations points might correspond to a particular ping frequency,and/or the calibrations points might correspond to a particular set ofping frequencies. The temporal characteristics of the pinging may bedifferent so as to detect different in-situ conditions. For example,when a vehicle is operated over Botts' dots (referring to roundnon-reflective raised pavement markers usually made with plastic,ceramic, thermoplastic paint, glass or occasionally metal), the tire ortires of the vehicle can undergo periodic deformation, which period isdependent on the speed of the vehicle and the distance between a firstBotts' dot 346 and a next Botts' dot. As shown, the deformation may bedifferent based various conditions (such as, warm ambient conditions,cold ambient conditions, conditions of low tire pressure, etc.).Moreover, the different deformations may be caused by specific roadconditions such as a road seam 347 or a small road defect 348. Any ofthe foregoing condition-specific signals and/or any road conditions canbe detected based on signals being returned in response to a ping orother stimulation. The foregoing discussion of FIG. 3E includesprocessing of a first set of example condition signatures. Additionalsets of condition signatures are discussed in further detail as follows.

FIG. 3F1 shows a second set of example condition signatures 3F100 thatare emitted from tires formed of layers of carbon-containing tunedresonance materials. The example condition signatures 3F100 or anyaspect thereof may be emitted in any environment. FIG. 3F1 illustratesmultiple body ply and/or tread layer (such as, body ply and/or treadlayer #1, body ply and/or tread layer #2, and body ply and/or treadlayer #3) of a new tire. The term “ply”, as used in this example andelsewhere with reference to any one or more of the presentedimplementations, can refer to a ply or layer within a body of the tire,or—alternatively—a layer of the tire tread protruding radially outwardaway from the body of the tire intended for contact with hard pavement,or the earth for off-road tires). In example, the first body ply and/ortread layer is formulated (referring to being created with a specificformula) with tuned carbons such that the first body ply and/or treadlayer resonates at 1.0 GHz when stimulated with a 1.0 GHz ping stimulus(such as, first ping 374). Similarly, the second body ply and/or treadlayer is formulated with tuned carbons such that the second body plyand/or tread layer resonates at 2.0 GHz when stimulated with a 2.0 GHzping stimulus (such as, second ping 376). Further, the third body plyand/or tread layer is formulated with tuned carbons such that the thirdbody ply and/or tread layer resonates at 3.0 GHz when stimulated with a3.0 GHz ping stimulus (such as, third ping 378). As shown by firstresponse 382, second response 384, and third response 386, allthree-body ply and/or tread layer are responsive at their respectivetuned frequencies.

A transceiver antenna can be positioned in and/or on the wheel well ofthe corresponding tire. Systems handling any such generated responsesignals can be configured to distinguish from other potential responsesarising from the other surfaces, such as the remaining non-target tiresof the vehicle, for example. For example, even though the right fronttire mounted on the right front wheel of the vehicle might respond to aping that is emitted from a transceiver antenna located in the leftfront wheel well of the vehicle, the response signal from the rightfront tire will be significantly attenuated (and recognized as such) ascompared to the response signals from the left front tire of thevehicle.

When the transceiver antenna is located in the wheel well of acorresponding tire, the response from the corresponding tire will beattenuated with respect to the ping stimulus. For example, the responsefrom the corresponding tire can be attenuated with respect to the pingstimulus by 9 decibels (-9 dB) or more, or can be attenuated withrespect to the ping stimulus by 18 decibels (-18 dB) or more, or can beattenuated with respect to the ping stimulus by 36 decibels (-36 dB) ormore, or can be attenuated with respect to the ping stimulus by 72decibels (-72 dB) or more. In some cases, a ping signal generator isdesigned to be combined with a transceiver antenna located in the wheelwell so as to cause the ping response of a corresponding tire to beattenuated by not more than 75 dB (-75 dB).

FIG. 3F2 depicts a third set of example condition signatures 3F200 thatare emitted from tires after wear-down of some of the carbon-containingtuned resonance materials. As an option, one or more variations ofexample condition signatures 3F200 or any aspect thereof may beimplemented in the context of the architecture and functionality of theimplementations described herein. The example condition signatures 3F200or any aspect thereof may be emitted in any environment.

In this example, the tire has undergone wear. More specifically, theoutermost body ply and/or tread layer has been worn away completely. Assuch, a ping stimulus at 1.0 GHz would not result in a response from theoutermost ply. This is shown in the chart as a first responseattenuation 387. As the tire continues to undergo tread wear, pingresponses from the next body ply and/or tread layer and ping responsesfrom the next successive body ply and/or tread layer and so on will beattenuated, which attenuation can be used to measure total tread wear ofthe tire. As an alternative, the same tuned carbons can be used in allply. The tread wear of the tire as well as other indications can bedetermined based on the returned signal signatures from the tire.

FIG. 3F3 depicts a graph of measured resonant signature signal intensity(in decibels, dB) against height (in millimeters, mm) of tire treadlayer loss, according to some implementations. As shown here,carbon-containing microstructures and/or microstructural materials canbe incorporated into sensors or, in some configurations, entire layersof one or more tire treads at a given concentration level, or multipledissimilar concentration levels (in each of the one or more tire treadlayers) to achieve the unique deterioration profile shown. That is, themeasure resonant signature (referring to the identifying “signature” ofa particular tire tread layer in question) can be ‘pinged’, as sodescribed herein, by one or more RF signals to demonstrate theattenuation of that emitted signal as shown.

A new tire tread layer can be configured to indicate a signal intensity(measured in decibels, dB) of approximately 0. That intensity can changeproportionate to the extent of deterioration of that tire tread layer.For instance, a 2 mm height loss of a tire tread layer, presumedly thetire tread layer in contact with pavement, can correspond with themeasure resonant signature signal intensity profile shown. A ‘ping’signal at 6.7 GHz can be measured at an intensity level of about 9 dB,or so, and so and so forth.

Accordingly, unique concentration levels, chemistries, dispersions,distributions and/or the like of the carbon-containing microstructurescan be embedded (or, in some cases, placed on one or more surfaces of)tire tread layers to achieve a unique and readily identifiable measuredresonant signature signal intensity as shown. A user of such a systemcan therefore immediately be notified to the exact extent and locationof tire tread wear as it occurs during driving, rather than beingrestricted to observe the tires while the vehicle is in a stationarycondition, a process that can be both time-consuming and cumbersome.

FIGS. 3G1 and 3G2 depict schematics of example conventional carbonmaterial production chains such as those described by Anzelmo, et al.,in U.S. Pat. No. 10,428,197 entitled “Carbon and Elastomer Integration”issued on Oct. 1, 2019, incorporated herein by reference in itsentirety. FIG. 3G1 shows a schematic of an example conventional carbonmaterial production chain 3G100, in comparison to FIG. 3G2, which is anexample of a carbon material production chain 3G200 used to produce thecarbon-based microstructures described herein. In the conventionalcarbon material production chain 3G100, as illustrated in FIG. 3G1, rawmaterials such as carbon black 3G102, silica 3G104, and other chemicals3G106 can be transported to entering a manufacturing facility 3G110,where they are formulated into an elastomer compound and then processedinto a finished product, such as (rubber-based and pneumatic) tires3G120.

A conventional tire supply can include the preparation of raw materials(such as rubber bales, carbon filler, textiles, steel and otheradditives), building the tire components (including extruding elastomercompounds for the tread and sidewalls), and then building the tire 3G120(including curing the tire, and inspecting the finished tire). Thecarbon microstructure production, the mixing of the elastomer compounds,and optionally building the finished product (such as automobile tires),can be done on-site, as well as (optionally) the nano-mixing ofmaterials as well.

In contrast to conventional carbon-inclusive tire production aspresented by conventional carbon material production chain 3G100 in FIG.3G1, hydrocarbons 3G202 and silica 3G204 are mixed (such as by beingintegrated together) on-site in a reactor 3G206 at a manufacturingfacility 3G208, then integrated with elastomer raw materials (such asrubber) to produce an elastomer compound, prior to processing into afinished product, such as tires 3G208. The differentiation between FIGS.3G1 and 3G2 shows potential benefits, including eliminating the need fortransporting difficult to handle carbon black materials and reducingenergy consumption by integrating materials together during the carbonproduction process.

Alternatively, the conventional supply chain shown in FIG. 3G1 can beused in conjunction with the present graphene-based carbon materials.The carbon materials can be produced at one site, and then the carbonmaterials and other component materials can be transported to amanufacturing facility where they are formulated into an elastomercompound and then processed into a finished product, such as tires.

Another benefit of using the present graphene-based carbon materials isthe improved purity compared to carbon black. Impurities in carbon black(such as residual oil) require the carbon to be labeled as carcinogenic.Provided graphene-inclusive carbon-based microstructures have lowervolatile organic compounds (VOCs) than carbon black, and therefore donot result in residual oil on the surface of the produced elastomermaterial. Alternatively, the carbon-based microstructures have a lowerconcentration of residual hydrocarbons (such as polycyclic aromatichydrocarbons) compared to carbon black, resulting in less residual oilon the surface of the produced elastomer material. The carbon materials(inclusive of carbon-based microstructures) described herein alsocontain low concentrations of contaminants (such as ash, metals, andother elemental contaminants) compared to conventionally processedcarbon black or graphene. Also, there can be minimal CO₂, NO_(N), andSO_(x), emissions as production by-products. All these benefits resultin the present carbon materials being safer to handle and moreenvironmentally friendly than the conventional carbon black that is usedfor elastomers.

The reduced concentration of impurities of the present carbon-basedmicrostructures compared to carbon black is also a benefit forprocessing the carbon materials (such as carbon post-processes, andelastomer compounding). For example, conventional carbon blackprocessing equipment can require specialized systems to process thetoxic carbon black particles. In contrast, specialized systems are notneeded to process the present non-toxic or low toxicity materials.

There are three properties that can affect the ability of a particularcarbon material to reinforce elastomers: (1) surface area; (2)structure; and, (3) surface activity. Also, impurities, such as coke,ash and moisture can be important to the effectiveness of a carbonmaterial filler in an elastomer. Surface area refers to the total areaof the carbon material surface, including that which is available tointeract with the elastomer. Particle size and shape can affect thesurface area. Smaller carbon-based microstructures (such as less than100 nm in average diameter) typically fuse together to form largeraggregates (such as 1-10 microns average diameter). Structure describesthe shape of the aggregate. The structure can be affected by the numberof particles fused together and the configuration of the particleswithin the aggregate. For example, aggregates with larger numbers ofparticles can have complex shapes with large void volumes created. Thestructure can affect the degree of mixing of the carbon and the polymer(such as voids can be filled with the polymer), which can affect theproperties of the elastomer/carbon compound.

Also, surface activity, which refers to the strength of the surfaceinteraction between the carbon filler material and the polymer, canimpact the dispersion properties of the carbon materials within theelastomer. Compound mechanical properties such as tensile strength, tearstrength, and abrasion resistance can be affected by surface area of thecarbon filler material. Other compound mechanical properties such asviscosity, shrinkage, and modulus can be affected by the structure ofthe carbon filler material. Surface area also can affect some compoundmechanical properties such as hysteresis. Structure can also affect flexfatigue and abrasion resistance in reinforced elastomeric compounds.Surface activity can affect compound mechanical properties as well, suchas modulus, hysteresis, and abrasion resistance.

Properties and procedures related to waste energy harvesting andpowering in vehicles, any one or more of which can influencecarbon-inclusive material performance in the disclosed systems, caninclude powering resonators embedded within tire plies. For example,capabilities related to waste energy harvesting and powering in vehiclescan include application spaces including at least the following:composites used in vehicles for harvesting energy from vehicular motion;vehicle tires for harvesting energy from vehicular motion; energycapture devices positioned in and around heat sources such as steampipes or exhaust pipes; and, industrial uses for harvesting energy fromequipment motion.

Thermoelectric power generation functionality can also be, in someimplementations, at least partially integrated into tires for energytransfer to occur within a vehicle wheel well. Such energy transfer caninclude: a flow of charge carriers between the hot and the cold regions(of the tire) to create a voltage difference, therefore allowingthermoelectric generators (TEGs) to still function in the dark, TEGsalso have no moving parts, which allows for continuous operation; TEGscan be placed as layers in tire treads, carbons tuned for conductivityand doped N/P can produce significant power from waste heat >10 mw/cm²,where even small temperature changes (such as Δ10° C.) can yieldapproximately 3.5 W+ to provide usable harvested power.

FIG. 4A illustrates a schematic diagram representative of a flow (withinsemi-conducting materials incorporated within materials of vehiclecomponents) of charge carriers between hot and cold regions to create avoltage difference to allow thermo-electric generators (TEGs) to operatein low or no light conditions. Semiconductor 4A00 can be incorporatedwithin plies of the body of a vehicle tire to capture heat transfer froma high temperature region including locations 4A02 and 4A04 throughn-type and/or p-type semiconducting materials 4A06 to provide electriccurrent through circuit 5B10 to power, for example, any of the discloseresonators.

FIG. 4B illustrates carbon-based materials incorporated into plieswithin the body or treads of a tire tuned for electric conductivityand/or doped to produce power from waste heat. Layered positive-negative(PN) junction semiconducting materials segmented for voltage 4B02 can beincorporated within walls of the body of a tire, or treads extendingtherefrom, and thus provide electric current to power the resonator asso described, which may include components such as an oscillator,resonant circuit, and rectifier, all operating in substantiallyconventional formats.

FIG. 4C illustrates a chart 5D00 for comparing output power against amagnitude of heat flux (delta of degrees Celsius) related tothermoelectric generation functionality integrated into tires.Assumptions include that TEG devices include bismuth telluride (Bi₂Te₃)having a Seebeck coefficient (referring to a measure of the magnitude ofan induced thermoelectric voltage in response to a temperaturedifference across that material) such as approximately −287 μV/K at 54°C. and/or demonstrating the relationship ZT=S2T/ρκ˜1. Carbon-basedmicrostructures can be tuned and incorporated within TEG devices topotentially also reach Seebeck performance (referring to a bismuthtelluride inclusive TEG device) performance and flexural ability.Generally, output power (in watts, W, per tire) generated by such TEGdevices can increase with larger temperature gradients.

Carbon-based microstructures can be incorporated into thermoelectric(TEG) devices by being placed as layers in composite components stacks,carbons properly tuned for conductivity and doped negative and/orpositive (N, P, respectively) semiconducting materials can producesignificant power from waste heat >10 mw/cm², such that a temperaturegradient of approximately 200 degrees F. can generate approximately 35W, or more. Such TEG devices incorporating the disclosed carbon-basedmicrostructures can be included in, for example, vehicle engine coversof conventional internal combustion engines to efficiently captureemitted radiant heat energy during engine operation for storage and/orlater re-use by providing usable electric current to power resonators.

FIG. 5A illustrates various example schematic diagrams 5A00 of a layeredpositive-negative (PN) junction type semiconductor material incorporatedinto engine components for electric power harvesting. The layered PNsemiconductor can be segmented for precise voltage control andincorporated within an engine cover, heat shields, or exhaustcomponents. And, foam materials may be used to absorb vibrational and/orthermal energy for power harvesting. As a whole, these devices, whencombined with any one or more of the aforementioned systems and devicescan be used to supplement energy harvesting and re-use capabilities topower resonators as needed to efficiently pin-point vehicle componentwear.

Tire diagnostic related devices can be, in some implementations, poweredby piezoelectric energy generators and/or the like. Piezoelectricity isthe electric charge that accumulates in certain solid materials (such ascrystals) in response to applied mechanical stress. The piezoelectriceffect results from the linear electromechanical interaction between themechanical and electrical states in crystalline materials with noinversion symmetry. The piezoelectric effect is a reversible process:materials exhibiting the piezoelectric effect (the internal generationof electrical charge resulting from an applied mechanical force) canalso exhibit the reverse piezoelectric effect, the internal generationof a mechanical strain resulting from an applied electrical field. Here,tire deformation or strain monitoring can indirectly provide the degreeof friction between the tires and road surface (which the tirescontact), which can be used for optimization of automobile tire controlsystems. Tire wear information can be wirelessly transmitted to areceiver positioned within the wheel well housing the tire of interestbased on a resonant sensor platform. Tire information can be transferredvia telemetry into a vehicle navigation system.

In some implementations, one or more of the carbon-based microstructuresused with the presently disclosed systems and materials, includingcarbon nano-onions (CNOs), can be used to form piezoelectric-layering insensors on the surface of or embedded within vehicle components, such astires. Also, graphene can be used to create energy harvesting patcheswith can be integrated into the tire. The CNOs and/or graphene can beprepared to collect, retain, and supply power (such as in the form ofelectric current) to resonators for use in identifying, with exactingaccuracy, location of vehicle component degradation, such as tire wear.

Tuned carbon materials, such as the micro-carbon nano-tubes (m-CNTs)shown in a graph 5B00 in FIG. 5B, can more accurately assist in thesensing of the tire tread wear (such as by powering resonators) due totheir large innate capacitance. In comparison to metals, CNOs canprovide a form of enhanced carbon to realize piezoelectric energygeneration.

For usage in conjunction with any one or more of the systems, methods,and materials presented earlier, CNOs can be used to createpiezoelectric generators that power, for example a wireless strainsensor position on the side (such as within an inner liner) of a tire tomonitor and detect tire damage. Potential tire deformation or strain canbe determined or calculated from the degree of friction from the roadsurface, where such information can then be used to optimize relatedautomobile tire control systems. Tire related information, for example,can be wirelessly transmitted (after being calculated based on signalfrequency shift and/or attenuation behavior as discussed earlier) toappropriately-equipped receivers that may be positioned within the tireand/or may work with resonators to provide a total tire informationsolution. Disclosed implementations can work with conventional telemetrymethods and devices to communicate vehicle component wear relatedinformation to, for example, a vehicle navigation system.

FIG. 5B illustrates the graph 5B00 of conventional materialsincorporated within rubber of a vehicle tire, comparing normalizedcapacitance (C/C₀) against rubber thickness (mm). As shown, thepresently disclosed m-CNTs consistently outperform traditional materialssuch as silver and gold as relating to normalized capacitance comparedto the thickness of rubber of materials into which the silver, gold, orm-CNTs (which may be incorporated in piezoelectric, thermoelectric, orother advanced energy harvesting and resupply functionality). Thepresently disclosed carbon-based nanomaterials match or exceedperformance figures for that shown for m-CNTs.

FIG. 6A illustrates a schematic diagram 6A00 showing a complete tirediagnostics system and apparatus for tire wear sensing throughimpedance-based spectroscopy. A tire 6A00, such as a pneumatic rubbertire filled with air or nitrogen gas (N2), can include traditional tirecomponents including a body 6A20, an inner liner 6Al2, a bead fillerregion 6A22, a bead 6A16, one or more belt plies 6A04, 6A06, 6A08, and6A10, tread 6A02, and impedance-based spectroscopy wear sensing printedelectronics 6A18 (alternatively sensors including carbon-basedmicrostructures for signal frequency shift and attenuation monitoring bya resonator embedded within any one or more of the belt plies6A04-6A10).

As shown here, a wireless strain sensor can be placed on surfaces or onthe sides of the inner liner (or be embedded within) to monitor the tirecondition for automobile safety, (such as to detect damaged tires). Tiredeformation or strain monitoring can (indirectly) provide informationrepresentative of a degree of friction between the tires and contactingroad surfaces, which can then be used for the optimization of automobiletire control systems. The tire information can be wirelessly transmittedto a receiver positioned in the tire hub based on a resonant sensorplatform.

FIG. 6B illustrates a system 6B00 for providing tire wear-relatedinformation transferred via telemetry into a navigation system andequipment for manufacturing printed carbon-based materials. The system6B00 can function with any one or more of the presently disclosedsystems, methods, and materials, such as the sensors includingcarbon-based microstructures such that a redundant description of thesame is omitted. Impedance spectroscopy, also referred to asElectrochemical Impedance Spectroscopy (EIS), refers to a method ofimpedimetric transduction involving the application of a sinusoidalelectrochemical perturbation (potential or current) over a wide range offrequencies when measuring a sample, such as a sensor includingcarbon-based microstructures incorporated within one or more tire beltplies of a tire 6B02. Printed carbon-based resonators 6B04 can beincorporated within one or more tire components such as the tire beltplies, with each of the printed carbon-based resonators 6B04 having thegeneral oval configuration shown, or some other shape or configurationtailored to achieve specific desirable resonance properties suitable forefficient and accurate vehicle component wear detection throughmonitoring of frequency shift and/or attenuation (such as a firstresponse attenuation indicative of the wear of a tire body ply and/ortread layer having a natural resonance frequency of approximately 1.0GHz).

An assembly of rollers 6B10 capable of forming the printed carbon-basedresonators 6B04 includes a repository 6B12 (such as a vat) ofcarbon-based microstructures and/or microstructural material (such asgraphene), an anilox roller 6B14 (referring to a hard cylinder, usuallyconstructed of a steel or aluminum core which is coated by an industrialceramic whose surface contains millions of very fine dimples, known ascells), a plate cylinder 6B16, and an impression cylinder 6B18. Inoperation, graphene extracted from the repository 6B12 can be rolled,pressed, stretched, or otherwise fabricated by the rollers of theassembly of rollers 6B10 into the oval-shaped (or in any other shape)printed carbon resonators 6B04. No registration (referring to alignment)of the printed carbon resonators 6B04 for appropriate functioning of thesystem 6B00.

As such, any combination of the aforementioned features can be used tomanufacture a tire that has a resonator (referring to actual or“equivalent” tank, LC and/or resonant circuit, where carbon-containingmicrostructures themselves can resonate in response to emitted RFsignals from a transceiver, and/or from energy supplied by an advancedenergy source, such that other sensors, disposed into or onto any one ormore components such as the tread, a ply or plies, an inner liner, etc.of the tire can demonstrate frequency-shifting or signal attenuationproperties or behavior. The described resonator is not necessarilyrequired to be embodied as an actual electrical and/or integratedcircuit (IC). The described resonator can be realized simply as tunedcarbon-containing microstructures, to thus avoid common deteriorationconcerns that may arise when implementing traditional discrete circuitryin decomposable materials, such as tire tread layers. Such resonatorscan resonate in response to an externally-supplied ‘ping’ (such as thatsupplied by a transceiver located in the wheel well of vehicle), or theresonator can respond to being charged by a co-located (referring towithin the same tire tread layer, but possibly at a different locationwithin that tire tread layer), self-powered, self-pinging capabilityfacilitated by any variations or any number of power or chargegenerators (such as thermoelectric generators, piezoelectric energygenerators, triboelectric energy generators, etc.).

At any time when the tire is rolling or otherwise undergoingdeformation, any of the described resonators (and other resonatorsand/or resonant circuits) can be configured to emit and/or further emitoscillating RF signals (or other forms of electromagnetic radiation,depending on the overall configuration). As a vehicle tire experienceswear resultant from usage (such as on or off-road driving), tire treadlayers in contact with pavement or ground (earth) may experiencedeformation, either instantaneously or over time (such as that observedfrom being “squished”, referring to at least partial flattening ofsections of the exposed vehicle tire tread layers during rotation orrolling, and/or from lateral motion as experienced during turning,etc.), therefore resultant signal frequency-shift and/or attenuationbehavior may change pursuant to such “squishing” as associated signalscan oscillate over one or more known amplitude ranges. In addition, orin the alternative, as the tire undergoes deformation, observed signalscan oscillate within a known frequency range corresponding to aparticular resonator, allowing for precise and accurate identificationof the type of deterioration occurring while it is occurring, ratherthan requiring the driver, passengers, and/or other vehicle occupants toexist the vehicle, while it is stationary, to observe tire treadconditions. Such a frequency-shifting oscillation is observable as afrequency shift back and forth between two or more frequencies withinthe known frequency range.

A wireless-capable strain, such as a geometric measure of deformationrepresenting the relative displacement between particles in a materialbody that is caused by external constraints or loads, sensor positionedon sides of the inner liner can monitor tire condition for automobilesafety (such by detecting damaged tires). Additionally, tire deformationor strain monitoring can indirectly provide information related to thedegree of friction between tires and road surface, which can then beused for the optimization of automobile tire control systems. Such tireinformation can be wirelessly transmitted to a receiver (and/ortransceiver) positioned in the wheel hub based on a resonant sensor(such as an impedance spectroscopy, IS, sensor) platform.

FIGS. 6C-6D illustrate schematics including a schematic diagram 6C00 anda schematic diagram 6D00, both related to a resonant serial number-baseddigital encoding system 6C04 for determining wear of vehicle tiresthrough ply-print encoding. The resonant serial number-based digitalencoding system 6C04 may be incorporated and/or function with any of thepresently disclosed systems, methods, and sensors. The resonant serialnumber-based digital encoding system 6C04 offers digital encoding oftires through ply-print encoding and thus offers cradle-to-the-grave(referring to a full lifespan) of tracking of tires (and relatedperformance metrics) and a usage profile without requiring traditionalelectronic devices susceptible to routine wear-and-tear in the tires.

Along with tire wear sensing thru Impedance Spectroscopy (IS) and/orElectrochemical Impedance Spectroscopy (EIS), additional resonators canbe digitally encoded onto a printed pattern to provide a recognizableserial number for telemetry-based tire performance tracking.Accordingly, so-equipped vehicles can track tread wear, miles driventotal, age, etc., without requiring traditional radio-frequencyidentification systems (RFID) or other electronics of any kind. By beingprinted onto the body ply and/or tread layer incrementally, tiresincorporating the discussed printed carbon-based resonators can beinnately serialized.

FIG. 6G shows schematic diagram 6D10 for resonant serial number encodingin tires. The serial number “6E” is shown encoded in aspecially-prepared array of printed carbon resonators configured toresonate according to the ‘ping’ stimulus-response diagram 6D12 allowingfor convenient and reliable identification of that particular body plyand/or tread layer of the so-equipped vehicle tire.

FIG. 7 illustrates a schematic diagram 700 depicting various layers oftire belt plies 702 configured to generate electric power or currentthrough piezo-electric capabilities such as that outlined earlier, andmay be incorporated into any one or more of the example tires discussedherein in relation to the various presented systems, methods, andmaterials. Generally, such belt plies may be a part of a conventionalrubber pneumatic vehicle, such as an automobile, sport utility vehicle,light truck, or truck tire, which may include any one or more of a bead,a body, reinforcing belts, cap plies (which are optional), sidewalls,and tread, also optional, and absent on certain racing tires such asslicks.

In some implementations, regarding any one or more of the presentlydisclosed examples, thermoelectric generation can be based on theprinciples of Seebeck, Peltier, and Thomson effects, where the flow ofcharge carriers between the hot and the cold regions creates a voltagedifference.

Optimal thermoelectric materials (suitable for incorporation within thepresently disclosed TEGs) should possess a high-Seebeck coefficient(V=αΔT), high-electrical conductivity, and low-thermal conductivity tomaintain high-thermal gradient at the junction. The polarity of theoutput voltage can be dependent on the polarity of the temperaturedifferential across the TEG.

TEGs can be made up of solid-state daisy-chained circuits of inverselydoped pairs of thermoelectric structural posts, referred to as “legs”.The N- and P-type semiconductor legs can be placed electrically inseries and sandwiched between two thin thermally conductive ceramicplates. A commonly used semiconductor material is bismuth-telluride(Bi₂Te₃).

The thermoelectric module with the highest product of V_(max) (maximumvoltage)*Imax (maximum current) for a given size will provide the idealpower. Common modules can be square, ranging in size from about 10 mm to50 mm per side and can range from 2 mm to 5 mm in thickness. A notableperformance feature distinguishable over other alternative energygeneration devices are that TEGs can operate in the dark, which greatlyexpands the scope of potential applications. TEGs are also solid-statedevices with no moving parts, allowing for continuous operation and alsocontaining no materials that need to be replenished. And, in certainconfigurations, TEGs provide that heating and cooling capabilities canbe reversed.

In some examples, strain gauge sensors can be incorporated withinelastomeric materials to sense weight to determine the curb weight of,for example, a tractor and trailer. Such sensors can be designed totrigger an alarm if the tire demonstrates a weight or load imbalance(such as due to a cargo shift), and increased force.

TEGs can function with resonators incorporated in race tires filled withnitrogen gas to observe increases in other gas amounts (such as oxygenand/or argon) to be indicative of leaks or a potential upcoming tirerupture (blowout) situation. Tire construction can incorporate anycombination of TEGs, piezoelectric energy generators, triboelectricenergy generators and other advanced energy harvesting means to capture,retain, and repurpose energy during vehicle operation to provideelectric current needed for resonator oscillation to function with anyof the presented systems. Also, vehicle component wear and deteriorationinformation can be electronically forwarded by appropriately equippedsystems (mounted in the vehicle itself, or elsewhere at remotelocations) to inform interested parties and potentially law enforcementauthorities as well to provide high-quality ongoing holistic andreliable vehicle operational information. This information can be usedand considered for predictive sales (based on vehicle driving behavior),promotional sponsorship, insurance, time-on-road, etc.

FIG. 8 illustrates a schematic cut-away diagram 800 of a vehiclechassis, engine, and drivetrain to show powertrain losses (such as thosethat are non-usable for forward propulsion power) associated with aconventional vehicle. Any of the disclosed systems, methods andmaterials can be applied to counter-act such powertrain losses byeffectively capturing energy that would be otherwise lost to re-purposesuch energy to power any of the disclosed resonators for vehiclecomponent material deterioration detection through signal resonancemonitoring. For instance, in a conventional automobile powered by afront-mounted internal combustion engine (such as that shown by thediagram 800 in FIG. 8), an input 802 provides a traditional exhaustibleenergy source, such as gasoline, into the engine. Idling of the engineresulting in waste 804 of 17% of that input energy, while another 2% islose in accessory operation 806, 62% is lost due to engine friction,engine-pumping losses, and to waste heat (collectively referred to asengine-related losses 808), 5.6% is lost in drive train losses 810 dueto friction and slippage, leaving only 12.6% of residual energyavailable 812 to actually move the vehicle down the road.

FIG. 9 illustrates a schematic cut-away diagram of a vehicle equippedwith piezoelectric and/or thermoelectric electric current and/or powergenerators. A vehicle 900 (as shown to be a mini-compact, but canalternatively be any form of passenger vehicle, sedan, coupe, truck,sport utility vehicle, sports car, etc.) that can be powered by aconventional internal combustion engine, feature hybrid electric power,or operate exclusively on an electric-only basis featuring an electricmotor. In example configuration the vehicle 900 can include four tires912, an air conditioning (A/C) converter 914, drive motors 902, a powersteering 906, a horsepower (HP) distributor 910, an external chargingsocket 904, and a battery system 916. The vehicle 900 can be equippedwith piezoelectric energy generation means (such as generators, devices,motors, and/or the like) to capture energy and convert that capturedenergy into electric current useful for other applications or uses, suchas to power any of the presently disclosed resonators, resonantcircuits, and/or the like for accurate and precise detection of vehiclecomponent condition regarding wear and degradation.

Piezoelectricity, as introduced earlier, implies the electric chargethat accumulates in certain solid materials (such as crystals) inresponse to applied mechanical stress. The word piezoelectricity meanselectricity resulting from pressure and latent heat. Mechanistically,the nature of the piezoelectric effect is closely related to theoccurrence of electric dipole moments in solids. The latter can eitherbe induced for ions on crystal lattice sites with asymmetric chargesurroundings (as in BaTiO₃) or may directly be carried by moleculargroups (as in cane sugar). The dipole density or polarization(dimensionality [C·m/m³]) can be calculated for crystals by summing upthe dipole moments per volume of the crystallographic unit cell. Asevery dipole is a vector, the dipole density P is a vector field.

The change of polarization P when applying a mechanical stress is ofimportance for the piezoelectric effect. This might either be caused bya reconfiguration of the dipole-inducing surrounding or byre-orientation of molecular dipole moments under the influence of theexternal stress. Piezoelectricity may then manifest in a variation ofthe polarization strength, its direction or both, with the detailsdepending on:

-   -   the orientation of P within the crystal;    -   crystal symmetry; and    -   the applied mechanical stress.

The change in P appears as a variation of surface charge density uponthe crystal faces, such as a variation of the electric field extendingbetween the faces caused by a change in dipole density in the bulk. Forexample, a 1 cm³ cube of quartz with 2 kN (500 lbf) of applied force canproduce a voltage of 12,500 V.

Such principles can be configured to provide voltage and/or electriccurrent to any of the presently disclosed resonators for associatedfunctioning as discussed earlier, such as to deliver: (1) high power;or, (2) low power. High power applications can include capturingrotational energy generated out of a tire through a rotating hub,induction, or wireless means. Low power applications include integratedwith remote and/or on-board (referring to integrated with the vehicle900) energy harvesting systems (such as the disclosed TEG systems and/ortriboelectric energy generators). Integration with a distributed sensorarray activated by electromagnetic (EM) signal communication (at, forexample, 465 Mhz, or similar) can be used to facilitate backscatter orinductive coupling.

FIG. 10 illustrates various perspective schematic views of an advancedconceptual tire and various energy (current) delivery challenges. Tires1000 and/or 1002 can be Goodyear® BH03 Piezo Concept Tires, manufacturedby The Goodyear Tire & Rubber Company of Akron, Ohio, or any similarsuch advanced self-generating powered tire, where any of the disclosedsystems, methods, and materials (inclusive of carbon-containingmicrostructures) can be configured to function with such advanced tiresto be self-powered regarding provision of ongoing electric power toresonators for accurate vehicle component material deteriorationdetection. Tires 1000 and/or 1002 may feature tread 1004, sipes 1006 andoffer construction including carbon black, referred to as “ultra-black”texture for effective heat absorption captured by thermoelectric (TE)power generators or capabilities.

With relation to incorporation into any one or more of the presentlydisclosed example carbon-based microstructures incorporated into tirematerials, types of suitable carbon include graphene and graphenerelated materials. Graphene refers to an allotrope of carbon in the formof a single layer of atoms in a two-dimensional hexagonal lattice inwhich one atom forms each vertex. It is the basic structural element ofother allotropes, including graphite, charcoal, carbon nanotubes andfullerenes. It can also be considered as an indefinitely large aromaticmolecule, the ultimate case of the family of flat polycyclic aromatichydrocarbons.

Graphene has a theoretical specific surface area (SSA) of 2,630 m²/g.This is much larger than that reported to date for carbon black(typically smaller than 900 m²/g) or for carbon nanotubes (CNTs), from≈100 to 1000 m²/g and is like activated carbon. Intrinsic properties ofgraphene include: high strength (per unit area), thermal conductivity inthe approximately 3,000 W/mK to approximately 5,000 W/mK range,capabilities to accommodate n-type conductivity by doping with certainelements such as nitrogen (N), sulfur (S), boron (B), phosphorous (P),fluorine (F), and/or chlorine (Cl).

The formula ZT=σS²T/K provides a quantitative relationship regarding thethermoelectric (TE) performance of materials as measured and can bedefined as follows: S is the Seebeck coefficient (a measure of themagnitude of an induced thermoelectric voltage in response to atemperature difference across that material, as induced by the Seebeckeffect), “σ” and “κ” are the electrical and thermal conductivity,respectively, and T is the absolute temperature. Goals forthermoelectric conversion can include to increase electricalconductivity while concurrently decreasing thermal conductivity.

Graphene can require nano-structuring, such as to achieve lowdimensionality: dots (“0D”), tubes/ribbons (“1D”), or sheet (2D) andinterfaces (phonon scatterers) to reduce thermal conductance and bandgap engineering to increase electrical carriers (p/n), increasesensitivity/performance, preparing certain graphene sheet formats thatare not well-suited for “daisy-chaining” (referring to connectingseveral devices together in a linear series) within typical high power,thermopile architecture and can be prepared to be best suited assupporting substrate (such as for thermal management) for epitaxialgrown BiSbTe.

Graphene can also be used as a multifunctional element offering any oneor more of the following advantages: allowing for combination with a (orto function as) thermal conductor (such as for heat management/PMCcomposite system; graphene-on-graphene materials),strengthener/reinforcement, distributed sensor (health: pressure,friction, shear) and to act as an energy harvester.

FIG. 11 is a side-view schematic diagram of a vehicle tire 1100incorporating graphene-filled rubber and contacting a ground orpavement. As shown, the vehicle tire 1100 includes a tire rim (ground)1102, and a steel belt (conductor) 1104 wrapped circumferentially aroundthe vehicle tire 1100. Graphene-filled rubber can be incorporated in orotherwise used to form one or more of the tire plies of a body of thetire. Such graphene-filled rubber can offer a conductive percolationthreshold (referring to the lowest concentration of filler at whichinsulating material can be converted to conductive material, meaningthat percolation threshold is the lowest concentration of fillermaterial, such as graphene-filled rubber, at which electrical pathway isformed throughout a sample). The tire can support its weight asreflected as a load 1106 and/or other weight bearing down on the tire,such as through a vehicle chassis or of the occupants, when the vehicleis loaded.

The vehicle tire 1100 can be equipped with triboelectric powergenerators in one or more plies of the body of the tire to supplycaptured energy in the form of usable electric energy to the resonatorsas disclosed earlier. Triboelectric energy conversion principles, asemployed here, support the conversion of mechanical energy intoelectricity, coupling triboelectric friction and electric induction topower sensors to diagnose, in an ongoing manner, the general health(referring to wear and degradation) of the tire.

Under normal (every commuting use) conditions, approximately 5 to 7% ofenergy generated by friction encountered between the vehicle tire 1100and the ground (such as roadway pavement) can be dissipated. Withouttriboelectric generators (or other advanced energy recovery means) torecover and retain such dissipated energy, the energy can be undesirablylost to the surrounding environment. Therefore, any of the presentlydisclosed carbon-based microstructures, such as those self-nucleatedin-flight in a reaction chamber or reactor from a carbon-containinggaseous species such as methane (CH₄), as disclosed by Stowell, et al.,in U.S. patent application Ser. No. 16/785,020 entitled “3DSelf-Assembled Multi-Modal Carbon-Based Particle” filed on Feb. 7, 2020,can be used to form sensors suitable to indicate vehicle component wearor degradation as discussed earlier.

Alternatively, or in addition, such carbon-based microstructures can beincorporated within the triboelectric energy generators themselves, andbe optimized to create a carbon-inclusive triboelectric conductor withadjustable (tunable) polarizability and able to be organized and/orconnected in series to accommodate a variety of power supply andgeneration scenarios or needs. Carbon-inclusive triboelectric energygenerators, as so described, can optionally be uniformly interspersedthroughout the entirety of a given tire ply, extending across the entirewidth of the tire, as well as circumferentially around the tire, insteadof being localized at (smaller than the width of the tire) localizedsensors. Therefore, such entire-tire-ply-width carbon-inclusivetriboelectric energy generators (and/or localized sensors incommunication with localized triboelectric energy generators distributedthroughout one or more tire plies) both can offer the followingbenefits:

-   -   high contact area at surface of tire for optimum charge        generation/surface electrification (ablation—referring to the        removal or destruction of material from an object by        vaporization, chipping, or other erosive processes, such as        being due to friction, creation of a new surface, and possible        changes in resistance and potentially related to tread        wear/lifetime);    -   tuned graphene and rubber composite materials can be optimized        for permittivity related electrostatic induction (referring to a        redistribution of electric charge in an object, caused by the        influence of nearby charges, to create or generate static        electricity in a material by bringing an electrically charged        object near it, this causes the electrical charges to be        redistributed in the material, resulting in one side having an        excess of either positive (+) or negative (−) charges);    -   graphene can be tuned to achieve optimum end-use application        area specific tire properties (such as optimization for wet or        dry handling, rolling resistance, etc.), and charge generation        (wettability); and    -   vibrations of the tire (loading and unloading, referring to        material flexure, could potentially relate to impedance changes)        can be captured and transformed into useful electric power.

Vehicle specific applications of triboelectric generators as set forthhere are applied to capture and re-use of the approximately 5 to 7% ofenergy otherwise lost due to rolling friction between a tire and thepavement with which it is in contact with. Specifically, ground surfacescontaining silica, cement, and metal (or metal-containing compositematerials) can act as electron donating materials that contact withelectron accepting materials in the carbon-based microstructures, suchas graphene, incorporated within sensors or entire plies of the body of,for example, a rubber pneumatic tire.

The role of graphene, referring particularly to, in some examples, 3Dhierarchical carbon-based microstructures synthesized fromagglomerations containing multiple graphene sheets coupled together, canbe tuned to act as an electrical conductor at its percolation threshold(referring to the lowest concentration of filler at which insulatingmaterial is converted to conductive material) and provide a relativelyhigh contact area at exposed surfaces of the tire for optimum chargegeneration. This may hold true especially for configurations in whichthe entire width of one or more tire plies incorporates at least somecarbon-based microstructures, making that entire body ply and/or treadlayer at least partially electrically conductive. Conductive materialscan accommodate charge generated by triboelectric generators fromablation (referring to the removal or destruction of carbon-containingrubber in the tire body ply and/or tread layer upon contact with thepavement causing vaporization of that material).

Moreover, graphene incorporated within the tire body ply and/or treadlayer can serve multiple desirable purposes including being tuned toachieve optimum tire properties, such as being tuned for optimumhandling under wet or dry conditions, rolling resistance, etc. Vibrationof the tire during loaded and unloaded condition, could also impactobserved impedance changes within such a partially conductive tirecapable of capturing and repurposing generated charge for materialdeterioration detection purposes.

FIGS. 12A-12C illustrate schematic diagrams 1200 of charge generation ona rolling wheel (equipped with a single electrode and a copper-laminatedpolydimethylsiloxane, PDMS, patch) to demonstrate incremental chargegeneration of a wheel rolling on ground such as pavement of a roadway.Any one or more of the presently disclosed carbon-based nanostructures,whether used to form sensors on surfaces, embedded within tire plies, ormixed within rubber formulations to form carbon-inclusive tire plies,can function with triboelectric energy generators that include thedesigns shown by the schematic diagrams 1200. As shown, triboelectricenergy generators can have the following components: metal sheets 1206that can be connected to an electrical load 1204 (referring to anelectrical component or portion of a circuit that consumes, active,electric power), which is in turn connected to a metal film 1202 incontact with a polymer film 1208 that contacts a ground 1210.

That is, equipment shown by the schematic diagrams 1200 can function toprovide electric power to resonators to electronically communicate withcarbon-based microstructures in sensors and elsewhere within or on atire body ply and/or tread layer and can accommodate at least thefollowing principles, capabilities, and/or observations:

-   -   A design of single-electrode triboelectric nanogenerator        (S-TENG) using rough PDMS thin film to simulate the tire surface        can effectively scavenge the wasted friction energy from rolling        tires;    -   The S-TENG design is very simple, scalable and able to be easily        integrated into a wide variety of potential end-use application        areas;    -   The triboelectric output increases monotonically (referring to a        function between ordered sets that preserves or reverses the        given order) with the load and moving speed of the tire;    -   The S-TENGs have been successfully implemented to the tires of a        toy vehicle and have instantaneously powered 6 commercial light        emitting diodes (LEDs) while the vehicle was moving on the        ground; and    -   This development provides a promising solution to improve fuel        efficiency of conventional vehicles or the cruising ability of        electric vehicles.

Triboelectric nanogenerators (TENG), generally, are energy harvestingdevices to convert mechanical energy into electricity based on theuniversally known triboelectric principle. Innovative design ofsingle-electrode TENG (S-TENG) using PDMS to simulate the tire surfacesfor scavenging the wasted friction energy from rolling tires have beendeveloped and can be integrated with the presently disclosed systems,methods, and materials. By fixing the PDMS S-TENG on a rubber wheel, theperformance of scavenging friction energy has been successfullysystematically investigated. The electric output of the S-TENG-on-wheeldemonstrated monotonical increase with the increase of the moving speedand weight load of the wheel.

Maximum instantaneous power has been obtained to be at approximately1.79 mW at a load resistance of 10 MΩ, corresponding to a highest energyconversion efficiency of 10.4%. And, arrays of multiple S-TENGs havebeen implemented to the tires of a toy vehicle and instantaneouslypowered 6 commercial green light emitting diodes (LEDs) while thevehicle was moving on the ground. This successful demonstration supportsa promising solution to scavenge the wasted friction energy from rollingtires, which may improve the fuel efficiency or the cruising ability ofelectric vehicles and may power the presented resonators.

FIG. 12D illustrates an example rotor 12D18 and a stator 12D10 arrangedin a configuration 12D00 to collectively function as an example of atriboelectric power generator or motor, according to someimplementations. Various known materials can be used, nevertheless theexample shown in the configuration 12D00 can include (at a minimum): anouter shell 12D02, a copper layer 12D04, a fluorinated ethylenepropylene (FEP) material is a copolymer of hexafluoropropylene andtetrafluoroethylene (and differs from the polytetrafluoroethylene resinsin that it is melt-processable using conventional injection molding andscrew extrusion techniques), an aluminum roller 12D16, a sponge layer,and an acrylic core 12D14.

In operation, the acrylic core 12D14 can rotate in a direction 12D08 andbe wrapped by multiple layers, each layer of the multiple layerssurrounding and in contact with both a preceding and succeeding layer.That is, the acrylic core 12D14 can be surrounded by the sponge layer12D06, that may be inwardly compressible to reduce and later regainthickness as needed to accommodate charge capture and transfer, whichcan be surrounded by the copper layer 12D04 (that may include quantitiesof FEP dispersed therein and the outer shell 12D02.

The aluminum roller 12D16 can rotate opposite to the direction 12D14 asshown in an enlarged section 12D12 to harvest triboelectricallygenerated charge. Observed physical values and parameters (when, forexample, used in conjunction with any of the aforementionedtriboelectric power generation means) include the following (at aminimum):

-   -   At load resistance of 20 MΩ and rotation rate of 1000 r/min,        peak power density of 250 mW/m2;    -   Simultaneous powering of 16 spotlights in parallel and charging        a 200 μF commercial capacitor to 120 V in 170 seconds;    -   At a load resistance of 10 MΩ, measured power density of 15        mW/cm³; and    -   At a load resistance of ˜1 MΩ, and rotation rate of 1000 rpm,        peak power of 267 mW/cm².

FIG. 13A illustrates schematic diagrams relating to a vehicle equippedwith a system 13A00 (inclusive of triboelectric energy generators in,for example, an actual form, as realized as electric and/or discretecircuits, as well as a representative form, as an “equivalent” circuit,as to be further detailed below) incorporated in tires 13A04 of avehicle 13A02 (of any type, such as traditional pneumatic tires as wellas next-generation solid air-less tires). System 13A00 can include aconfiguration of an array of compressible hexagonal-structuredtriboelectric energy nanogenerators (CH-TENGs) 13A06 fixed within a body13A08 or within one or more tread layers of one of the tires 13A04.CH-TENGs 13A06 can be substantially like any of the triboelectric powergeneration means presently disclosed (and function accordingly), butwith each of the triboelectric energy generators having a substantiallyhexagonal shape. Other potential representations 13B02 are shown in FIG.13B.

CH-TENGs 13A06 can generate charge usable to create electric currentsuitable to power resonators capable of further emitting signals emittedby a transceiver 13A10 (capable of both transmitting and receivingelectromagnetic radiation in the form of signals). Certainconfigurations of the CH-TENGS 13A06 can also include traditionalelectronic components such as a rectifier and a capacitor to communicatewith a wireless tire pressure sensor that may be a part of atire-pressure monitoring system (TPMS) to provide a holistic tire wearmonitoring solution.

System 13A00 can include at least three (3) types of components,functionalities, and/or sub-systems related to the detection andcommunication of aberrations to the tire, including equipment thatfunctions by:

-   -   Emitting a RF signal, such as by a transceiver 13A10, or further        emitted by a resonator;    -   Resonating in response to an RF signal (more specifically,        generating a respective resonant signal by resonating in        response to an excitation signal), such as that performed by a        traditional LC, resonant and/or tank circuit (or any other        discrete circuit element), and/or carbon-containing        microstructures tuned to resonate and/or attenuate signals at        known frequencies and/or intensity levels; and    -   Shifting the frequency of and/or attenuating the RF signal, as        performed by sensors made of carbon-containing materials, or        entire surfaces such as vehicle tire tread layers and/or plies        including mixtures at fixed or vary concentration levels, etc.

Generally, resonators can be realized in discrete form, that is, as anLC circuit, also called a resonant circuit, tank circuit, or tunedcircuit. This type of resonator is an electric circuit consisting ofdiscrete components such as an inductor, represented by the letter L,and a capacitor, represented by the letter C, connected together. Thecircuit can act as an electrical resonator, an electrical analogue of anacoustic wave tuning fork, storing energy and emitting energy that isoscillating at the circuit's natural resonant frequency.

LC circuits can be used either for generating signals at a particularfrequency or picking out a signal at a particular frequency from a morecomplex signal; this function is referred to as “a bandpass filter”.They are key components in many electronic devices, particularly radioequipment, used in circuits such as oscillators, filters, tuners andfrequency mixers.

However, the incorporation of discrete electronic components into apotential high-abrasion area such as vehicle tire tread layers exposedto contact with pavement or the ground, for example, can be problematicin view of possible unwanted degradation and breakage of suchcomponents, such as traditional LC circuits as so described above, dueto wear and tear and/or increased temperatures, etc.

Accordingly, the resonators can be, in some implementations, made fromsolely carbon-containing microstructures and related materialsindependent of any discrete electronics. Such carbon-containingmicrostructures can form sensors that can be either embedded within tireplies of the body of the tire, or within tire tread layers, or both.Further, carbon-containing microstructures can be mixed into tireformative materials (such as rubber) to be present within one or moreplies and/or tire tread layers at, for example, varying, similar (oreven identical) concentration levels that may impact signal generationperformance.

Sensors, plies and/or tire tread layers made from carbon-containingmicrostructures can effectively and entirely replace traditionaldiscrete circuit components, such as the resonant circuit describedabove, by providing equivalent (at least substantially identical)functionality and performance, and can thus be represented by anequivalent circuit 13Al2, which can be powered by the CH-TENGs 13A06, ornot, by generating a respective resonant signal by resonating inresponse to an excitation signal (such as that emitted by atransceiver). An equivalent circuit refers to a theoretical circuit thatretains all of the electrical characteristics of a given circuit (suchas a resonant circuit), but is made up of linear, passive elements (andthus does not necessarily require the usage of traditional discretecircuit elements).

Accordingly, unwanted breakage of traditional discrete circuits can beavoided by implementing sensors, plies and/or tire tread layers madefrom carbon-containing microstructures that act as equivalent circuits.In such a configuration, there are no discrete electronic componentdevices installed inside the tire. Rather, the one or more various tiretread layers and/or tire body plies of the tire can be composed of(and/or otherwise include sensors made from) carbon-containing tunedmicrostructural resonance materials that resonate at a known frequencyor that resonate within a known frequency range to facilitate accurateand precise identification of component wear.

FIG. 13B illustrates various types of triboelectric energy generatorconfigurations 13B00 intended for incorporation within a vehicle tire.Such configurations can be substantially hexagonal, such as that shownby enlarged section 13B12, or take on any of the forms shown bystructures I-VI, shown by an example configuration schematic 13B02, anexample configuration schematic 13B04, an example configurationschematic 13B06, an example configuration schematic 13B08, an exampleconfiguration schematic 13B10, and an example configuration schematic13B12, respectively, during cyclical compression and decompressioncycles (referred to colloquially as being “squished”) proportionate totire body ply and/or tread layer contact with the ground, given that theCH-TENGs can be included within the tire plies (as shown in the body13A08 of the tire 13A04 shown in FIG. 13A) and compress according totire compression. Cyclical compression-decompression behavior canfacilitate electric charge harvesting capabilities of the CH-TENGs.

Generally, tire-pressure monitoring system (TPMS), which may be suitablefor incorporation with any one or more of the aforementioned examplesystems and structures, refers to an electronic system designed tomonitor the air pressure inside the pneumatic tires on various types ofvehicles. A TPMS reports real-time tire-pressure information to thedriver of the vehicle, either via a gauge, a pictogram display, or asimple low-pressure warning light. TPMS can be divided into twodifferent types—direct (dTPMS) and indirect (iTPMS). TPMS are providedboth at an OEM (factory) level as well as an aftermarket solution. Thetarget of a TPMS is avoiding traffic accidents, poor fuel economy, andincreased tire wear due to under-inflated tires through earlyrecognition of a hazardous state of the tires.

Any of the disclosed methods, systems and materials can functionallycombine with any type of TPMS to support TPMS functionality to provideadditional, heightened, tire deterioration information. As presented,iTPMS can monitor any of: speed, vibration, wheel radius, and can employmore advanced methods, including usage of Kalman filters (also known aslinear quadratic estimation, LQE, an algorithm that uses a series ofmeasurements observed over time, containing statistical noise and otherinaccuracies, and produces estimates of unknown variables that tend tobe more accurate than those based on a single measurement alone, byestimating a joint probability distribution over the variables for eachtimeframe) along with strain, temperature, and acceleration to determinedeformation and friction (essentially “piggybacking” off, referring torelying on the functionality of, existing anti-lock braking system, ABS,sensor suite). And, dTPMS can couple with or otherwise functionalityintegrate with the following capabilities and/or technologies (at aminimum):

-   -   Capacitive sensors and/or energy generators: two surfaces come        in contact (wheel rim, valve, Nb2O5 active material)    -   Strain gauge: polyimide based although film is much stiffer than        rubber (debonding)    -   Surface acoustic wave (SAW) sensors, which are a class of        microelectromechanical systems (MEMS) which rely on the        modulation of surface acoustic waves to sense a physical        phenomenon; the sensor transduces an input electrical signal        into a mechanical wave which, unlike an electrical signal, can        be easily influenced by physical phenomena; the device then        transduces this wave back into an electrical signal; changes in        amplitude, phase, frequency, or time-delay between the input and        output electrical signals can be used to measure the presence of        the desired phenomenon; SAW: interdigitated electrodes on        piezoelectric substrate;    -   Fabry-Pérot interferometer (FPI) or etalon is an optical cavity        made from two parallel reflecting surfaces (such as thin        mirrors); optical waves can pass through the optical cavity only        when they are in resonance with it;    -   Hall effect sensors, referring to devices that are used to        measure the magnitude of a magnetic field; its output voltage is        directly proportional to the magnetic field strength through it;        Hall effect sensors are used for proximity sensing, positioning,        speed detection, and current sensing applications tread        deformation (GaAs on ceramic);    -   MEMS (micro-electric mechanical systems, referring to the        technology of microscopic devices, particularly those with        moving parts)    -   Non-contact ultrasonic systems (mounted base of wheel rim inside        tire); and    -   Electric resistor-condenser parallel circuit integrated on steel        wire belt.

Graphene and/or other ordered carbon-based sensors can combine with theaforementioned TPMS systems and employ any one or more of the followingsensor types and/or variants:

-   -   Capacitive;    -   Strain gauge; and    -   Piezoelectric-based sensors (ZnO coated carbon nanotubes, CNTs).

FIG. 14A is a schematic side-view of a substrate assembly 14A00incorporating a substrate 14A04. The substrate assembly 14A00 be a partof an ABS sensor suite and can interact or function with any of thepresently disclosed systems, methods, and materials incorporating, forexample, carbon-based microstructures to provide power (in the formelectric current) to resonators. The substrate assembly 14A00 can have adiaphragm thickness 14A06 that can expand (or compress) near asilicon-containing region 14A02 in response to exterior force (shown bythe arrows), above a gap 14A08. The gap 14A08 can be disposed above anisolation layer 14A10 on top of a substrate electrode 14Al2.

FIG. 14B is a schematic view of a polyimide-based strain gauge system14B00 that can be configured to monitor tire pressure, including acomputing resource 14B02, a strain gauge 14B04 responsive to an externalapplied force 14B10, and a capability to miniaturized to accommodate anon-tire-ply-fitment 14B12 on a tire body ply and/or tread layer 14B08.The polyimide-based strain gauge system 14B00 can be a part of a TPMS incommunication with any of the presently disclosed systems, methods, andmaterials, to augment tire pressure detection capabilities with furtherdetailed tire condition deterioration-related information.

FIG. 14C is a schematic cut-away view of a hall sensor system 14C00configured to detect vehicle tire tread deformation and incorporatinggallium arsenide (GaAs) on ceramic. The hall sensor system 14C00 can bea part of a TPMS in communication with any of the presently disclosedsystems, methods, and materials, to augment tire pressure detectioncapabilities with further detailed tire condition deterioration-relatedinformation. The hall sensor system 14C00 can include a steel cord14C04, as a part of a vehicle tire. Gallium arsenide (GaAs) hall effectgenerators 14C06 function with a magnet 14C08 within a body 14C10 (of atire) above tread elements which contact the road (shown as a pavement14C12). Functioning of the hall sensor system 15D00 can generateelectric charge and/or current usable to power resonators to ascertaintire condition information during vehicle operation.

FIG. 14D shows a schematic diagram relating to a non-contact ultrasonicelectric resistor-condenser parallel circuit 14D00 integrated on a pair14D04 of steel wire belts 14D02 of within the body of a tire.Functioning of the non-contact ultrasonic electric resistor-condenserparallel circuit 14D00 can generate electric charge and/or currentusable to power resonators (as presently disclosed) to ascertain tirecondition information during vehicle operation. The pair 14D04 of thesteel wire belts 14D02 can be positioned a defined distance 14D10 apartto demonstrate a quantifiable dielectric constant 14D06 and/orresistivity 14D08 values.

FIG. 14E shows another suitable configuration of the non-contactultrasonic electric resistor-condenser parallel circuit 14E00(non-contact referring to the lack of contact between individual steelwire belts), where steel wires are electrically coupled and/or connectedwith corresponding electrodes as may be necessary to store and transferelectric charge and/or conduct electric current to power the resonatorsas disclosed herein.

FIG. 14F shows a simplified schematic diagram of a representation of thenon-contact ultrasonic electric resistor-condenser parallel circuit14D00 (as shown in FIG. 14D) which can be, in some implementations,another type of “equivalent circuit” that features no discrete circuitrybut instead implements a theoretical circuit composed ofcarbon-containing microstructures that exhibit all of the electricalcharacteristics of a given circuit. As an example, this equivalentelectric circuit can include carbon-containing microstructural resonantmaterials that mimic the functionality of at least a capacitor (C) andresistor (R) that may be configured as necessary to resonate as neededfor detection of frequency-shift behavior and/or signal attenuation asdemonstrated by resonant materials.

FIG. 14G shows a schematic diagram 14G00 of an electricresistor-condenser parallel circuit 14G10 (having multiple wires 14G12)integrated onto a steel wire belt 14G06 of a vehicle tire 14G02. Thesteel wire belt 14G06 can be in near a tire component (such as asidewall) 14G04 without interfering with a tire tread pattern 14G08. Theelectric resistor-condenser parallel circuit 14G10 can generate usableelectric charge and/or power or current through any one or more of theaforementioned means, such as by triboelectric principles, or otherwise,to provide such power to the resonators as presently disclosed.

FIGS. 15-17 depict structured carbons, various carbon nanoparticles,various carbon-based aggregates, and various three-dimensionalcarbon-containing assemblies that are grown over other materials. Thatdisclosed may be examples of the carbon-based microstructures asreferred to herein.

FIG. 18 illustrates a Raman shift plot for one or more of the structuredcarbons and/or the like shown in FIGS. 16-18. Peaks are observed at (oraround) approximately 2670 cm⁻¹, 1600 cm⁻¹, and 1380 cm⁻¹.

FIG. 19 illustrates a perspective view schematic diagram 1900 of anexample lattice-style arrangement 1908 of constituent elements (such asrubber) in a tire body ply and/or tread layer with resonant circuit(also referred to herein as a “resonator”) components, including anexample resonant circuit configuration 1902, an example resonant circuitconfiguration 1904, and an example resonant circuit configuration 1906embedded within or in-between the elements. Any conceivableconfiguration is possible for the resonant circuit components, wheresuch configurations can have an impact on oscillation and/or resonationcapabilities regarding further signal emission as may be relevant forascertaining tire deterioration as presently disclosed herein.

FIG. 20 is an example Raman intensity heat map or plot representative ofsignal attenuation associated with the resonant circuit shown in FIG. 19when incorporated into a vehicle tire body ply and/or tread layer and inoperation.

FIG. 21 is a schematic diagram showing an example configuration ofself-assembled carbon-based particles having various agglomerationpatterns (e.g., agglomeration pattern 2106, agglomeration pattern 2108,and agglomeration pattern 2110, as shown), any one or more of which canconstitute a concentrated region 2104 that can impact the resonationperformance of materials within which the carbon-based microstructuresare incorporated.

Usage Overview

Deployment Examples

Any one or more of the foregoing techniques and materials may becombined into a manufacturing process for surface sensors intended to beembedded in vehicle-related materials and/or surfaces, such as tire ply.An automotive surface sensor can be manufactured by selecting a carbonallotrope based at least in part on a specified frequency, mixing thecarbon allotrope with other ingredients of a composite material, andthen forming the automotive surface sensor using the composite material.The automotive surface sensor will resonate at the specified frequencywhen stimulated by electromagnetic emissions (RF signals) of thespecified frequency.

Further, any or all the foregoing techniques and materials may becombined into a manufacturing process for tires. An automotive tire canbe manufactured by selecting a carbon allotrope based at least in parton a specified frequency, mixing the carbon allotrope with otheringredients that are used in one or more tire materials, and thencombining the one or more tire materials with additional tire componentsto assemble the tire. The tire materials will resonate at a specifiedfrequency when stimulated by electromagnetic emissions of the specifiedfrequency. Moreover, such resonation can be caused by proximalelectromagnetic radiation (such as, a ping) of the specified frequency.Strictly as one example, a tuned antenna that emits proximalelectromagnetic radiation of the specified frequency can be in a wheelwell of a vehicle. In some situations, resonant structures that areapplied to, and/or incorporated with or within tire materials willresonate at a specified frequency when stimulated by electromagneticradiation emissions of the specified frequency. In some situations, suchresonance is measurable as an attenuation in the response signal.

Structured Carbon Overview

Additional Structured Carbon Examples

FIG. 22A through FIG. 22Y depict carbon-based materials, growths,agglomerates, aggregates, sheets, particles and/or the like, such asthose self-nucleated in-flight in a reaction chamber or reactor from acarbon-containing gaseous species such as methane (CH₄), as disclosed byStowell, et al., in U.S. patent application Ser. No. 16/785,020 entitled“3D Self-Assembled Multi-Modal Carbon-Based Particle” filed on Feb. 7,2020.

The shown carbon-based nanoparticles and aggregates can be characterizedby a high degree of “uniformity” (such as a high mass fraction ofdesired carbon allotropes), a high degree of “order” (such as a lowconcentration of defects), and/or a high degree of “purity” (such as alow concentration of elemental impurities), in contrast to the loweruniformity, less ordered, and lower purity particles achievable withconventional systems and methods.

The nanoparticles produced using the methods described herein cancontain multi-walled spherical fullerenes (MWSFs) or connected MWSFs andhave a high uniformity (such as, a ratio of graphene to MWSF from 20% to80%), a high degree of order (such as, a Raman signature with anI_(D)/I_(G) ratio from 0.95 to 1.05), and a high degree of purity (suchas, the ratio of carbon to other elements (other than hydrogen) isgreater than 99.9%). The nanoparticles produced using the methodsdescribed herein contain MWSFs or connected MWSFs, and the MWSFs do notcontain a core composed of impurity elements other than carbon. Theparticles produced using the methods described herein can be aggregatescontaining the nanoparticles described above with large diameters (suchas greater than 10 μm).

Conventional methods have been used to produce particles containingmulti-walled spherical fullerenes with a high degree of order but canlead to end products with a variety of shortcomings. For example, hightemperature synthesis techniques lead to particles with a mixture ofmany carbon allotropes and therefore low uniformity (such as less than20% fullerenes relative to other carbon allotropes) and/or smallparticle sizes (such as less than 1 μm, or less than 100 nm in somecases). Methods using catalysts can lead to products that include thecatalyst elements and therefore have relatively lower purity (referringto less than 95% carbon to other elements) as well. These undesirableproperties also often lead to undesirable electrical properties of theresulting carbon particles (such as, electrical conductivity of lessthan 1,000 S/m).

The carbon nanoparticles and aggregates described herein can becharacterized by Raman spectroscopy that is indicative of the highdegree of order and uniformity of structure. The uniform ordered and/orpure carbon nanoparticles and aggregates described herein can beproduced using relatively high speed, low cost improved thermal reactorsand methods, as described below.

The term “graphene”, as both commonly understood and as referred toherein, implies an allotrope of carbon in the form of a two-dimensional,atomic-scale, hexagonal lattice in which one atom forms each vertex. Thecarbon atoms in graphene are sp²-bonded. Additionally, graphene has aRaman spectrum with two main peaks: a G-mode at approximately 1580 cm⁻¹and a D-mode at approximately 1350 cm⁻¹ (when using a 532 nm excitationlaser).

The term “fullerene”, as both commonly understood and as referred toherein, implies a molecule of carbon in the form of a hollow sphere,ellipsoid, tube, or other shapes. Spherical fullerenes can also bereferred to as Buckminsterfullerenes, or buckyballs. Cylindricalfullerenes can also be referred to as carbon nanotubes. Fullerenes aresimilar in structure to graphite, which is composed of stacked graphenesheets of linked hexagonal rings. Fullerenes may also contain pentagonal(or sometimes heptagonal) rings.

The term “multi-walled fullerene”, as both commonly understood and asreferred to herein, implies fullerenes with multiple concentric layers.For example, multi-walled nanotubes (MWNTs) contain multiple rolledlayers (concentric tubes) of graphene. Multi-walled spherical fullerenes(MWSFs) contain multiple concentric spheres of fullerenes.

The term “nanoparticle”, as both commonly understood and as referred toherein, implies a particle that measures from 1 nm to 989 nm. Thenanoparticle can include one or more structural characteristics (suchas, crystal structure, defect concentration, etc.), and one or moretypes of atoms. The nanoparticle can be any shape, including but notlimited to spherical shapes, spheroidal shapes, dumbbell shapes,cylindrical shapes, elongated cylindrical type shapes, rectangularand/or prism shapes, disk shapes, wire shapes, irregular shapes, denseshapes (such as, with few voids), porous shapes (such as, with manyvoids), etc.

The term “aggregate”, as both commonly understood and as referred toherein, implies a plurality of nanoparticles that are connected togetherby Van der Waals forces, by covalent bonds, by ionic bonds, by metallicbonds, or by other physical or chemical interactions. Aggregates canvary in size considerably, but in general are larger than about 500 nm.

A carbon nanoparticle can include two (2) or more connected multi-walledspherical fullerenes (MWSFs) and layers of graphene coating theconnected MWSFs and can be formed to be independent of a core composedof impurity elements other than carbon. A carbon nanoparticle, asdescribed herein, can include two (2) or more connected multi-walledspherical fullerenes (MWSFs) and layers of graphene coating theconnected MWSFs. In such a configuration, where the MWSFs do not containa void (referring to a space with no carbon atoms greater thanapproximately 0.5 nm or greater than approximately 1 nm) at the center.The connected MWSFs can be formed of concentric, well-ordered spheres ofsp²-hybridized carbon atoms (which is in favorable contrast toconventional spheres of haphazardly-ordered, non-uniform, amorphouscarbon particles, which can otherwise fail to achieve any one or more ofthe unexpected and favorable properties disclosed herein).

The nanoparticles containing the connected MWSFs have an averagediameter in a range from 5 to 500 nm, or from 5 to 250 nm, or from 5 to100 nm, or from 5 to 50 nm, or from 10 to 500 nm, or from 10 to 250 nm,or from 10 to 100 nm, or from 10 to 50 nm, or from 40 to 500 nm, or from40 to 250 nm, or from 40 to 100 nm, or from 50 to 500 nm, or from 50 to250 nm, or from 50 to 100 nm.

The carbon nanoparticles described herein form aggregates, wherein manynanoparticles aggregate together to form a larger unit. A carbonaggregate can a plurality of carbon nanoparticles. A diameter across thecarbon aggregate can be a range from 10 to 500 μm, or from 50 to 500 μm,or from 100 to 500 μm, or from 250 to 500 μm, or from 10 to 250 μm, orfrom 10 to 100 μm, or from 10 to 50 μm. The aggregate can be formed froma plurality of carbon nanoparticles, as defined above. Aggregates cancontain connected MWSFs, such as those with a high uniformity metric(such as a ratio of graphene to MWSF from 20% to 80%), a high degree oforder (such as a Raman signature with an I_(D)/I_(G) ratio from 0.95 to1.05), and a high degree of purity (such as greater than 99.9% carbon).

Aggregates of carbon nanoparticles, referring primarily to those withdiameters in the ranges described above, especially particles greaterthan 10 μm, are generally easier to collect than particles or aggregatesof particles that are smaller than 500 nm. The ease of collectionreduces the cost of manufacturing equipment used in the production ofthe carbon nanoparticles and increases the yield of the carbonnanoparticles. Particles greater than 10 μm in size also pose fewersafety concerns compared to the risks of handling smaller nanoparticles,such as, potential health and safety risks due to inhalation of thesmaller nanoparticles. The lower health and safety risks, thus, furtherreduce the manufacturing cost.

A carbon nanoparticle, in reference to that disclosed herein, can have aratio of graphene to MWSFs from 10% to 90%, or from 10% to 80%, or from10% to 60%, or from 10% to 40%, or from 10% to 20%, or from 20% to 40%,or from 20% to 90%, or from 40% to 90%, or from 60% to 90%, or from 80%to 90%. A carbon aggregate has a ratio of graphene to MWSFs is from 10%to 90%, or from 10% to 80%, or from 10% to 60%, or from 10% to 40%, orfrom 10% to 20%, or from 20% to 40%, or from 20% to 90%, or from 40% to90%, or from 60% to 90%, or from 80% to 90%. A carbon nanoparticle has aratio of graphene to connected MWSFs from 10% to 90%, or from 10% to80%, or from 10% to 60%, or from 10% to 40%, or from 10% to 20%, or from20% to 40%, or from 20% to 90%, or from 40% to 90%, or from 60% to 90%,or from 80% to 90%. A carbon aggregate has a ratio of graphene toconnected MWSFs is from 10% to 90%, or from 10% to 80%, or from 10% to60%, or from 10% to 40%, or from 10% to 20%, or from 20% to 40%, or from20% to 90%, or from 40% to 90%, or from 60% to 90%, or from 80% to 90%.

Raman spectroscopy can be used to characterize carbon allotropes todistinguish their molecular structures. For example, graphene can becharacterized using Raman spectroscopy to determine information such asorder/disorder, edge and grain boundaries, thickness, number of layers,doping, strain, and thermal conductivity. MWSFs have also beencharacterized using Raman spectroscopy to determine the degree of orderof the MWSFs.

Raman spectroscopy is used to characterize the structure of MWSFs orconnected MWSFs used in reference to that incorporated within thevarious tire-related plies of tires as discussed herein. The main peaksin the Raman spectra are the G-mode and the D-mode. The G-mode isattributed to the vibration of carbon atoms in sp²-hybridized carbonnetworks, and the D-mode is related to the breathing of hexagonal carbonrings with defects. In some circumstances, defects may be present, yetmay not be detectable in the Raman spectra. For example, if thepresented crystalline structure is orthogonal with respect to the basalplane, the D-peak will show an increase. Alternatively, if presentedwith a perfectly planar surface that is parallel with respect to thebasal plane, the D-peak will be zero.

When using 532 nm incident light, the Raman G-mode is typically at 1582cm⁻¹ for planar graphite, however, can be downshifted for MWSFs orconnected MWSFs (such as, down to 1565 cm¹ or down to 1580 cm¹). TheD-mode is observed at approximately 1350 cm¹ in the Raman spectra ofMWSFs or connected MWSFs. The ratio of the intensities of the D-modepeak to G-mode peak (such as, the I_(D)/I_(G)) is related to the degreeof order of the MWSFs, where a lower I_(D)/I_(G) indicates a higherdegree of order. An I_(D)/I_(G) near or below 1 indicates a relativelyhigh degree of order, and an I_(D)/I_(G) greater than 1.1 indicates alower degree of order.

A carbon nanoparticle or a carbon aggregate containing MWSFs orconnected MWSFs, as described herein, can have and/or demonstrate aRaman spectrum with a first Raman peak at about 1350 cm⁻¹ and a secondRaman peak at about 1580 cm⁻¹ when using 532 nm incident light. Theratio of an intensity of the first Raman peak to an intensity of thesecond Raman peak (such as, the I_(D)/I_(G)) for the nanoparticles orthe aggregates described herein can be in a range from 0.95 to 1.05, orfrom 0.9 to 1.1, or from 0.8 to 1.2, or from 0.9 to 1.2, or from 0.8 to1.1, or from 0.5 to 1.5, or less than 1.5, or less than 1.2, or lessthan 1.1, or less than 1, or less than 0.95, or less than 0.9, or lessthan 0.8.

A carbon aggregate containing MWSFs or connected MWSFs, as definedabove, has a high purity. The carbon aggregate containing MWSFs orconnected MWSFs has a ratio of carbon to metals of greater than 99.99%,or greater than 99.95%, or greater than 99.9%, or greater than 99.8%, orgreater than 99.5%, or greater than 99%. The carbon aggregate has aratio of carbon to other elements of greater than 99.99%, or greaterthan 99.95%, or greater than 99.9%, or greater than 99.5%, or greaterthan 99%, or greater than 90%, or greater than 80%, or greater than 70%,or greater than 60%. The carbon aggregate has a ratio of carbon to otherelements (except for hydrogen) of greater than 99.99%, or greater than99.95%, or greater than 99.9%, or greater than 99.8%, or greater than99.5%, or greater than 99%, or greater than 90%, or greater than 80%, orgreater than 70%, or greater than 60%.

A carbon aggregate containing MWSFs or connected MWSFs, as definedabove, has a high specific surface area. The carbon aggregate has aBrunauer, Emmett and Teller (BET) specific surface area from 10 to 200m²/g, or from 10 to 100 m²/g, or from 10 to 50 m²/g, or from 50 to 200m²/g, or from 50 to 100 m²/g, or from 10 to 1000 m²/g.

A carbon aggregate containing MWSFs or connected MWSFs, as definedabove, has a high electrical conductivity. A carbon aggregate containingMWSFs or connected MWSFs, as defined above, is compressed into a pelletand the pellet has an electrical conductivity greater than 500 S/m, orgreater than 1,000 S/m, or greater than 2,000 S/m, or greater than 3,000S/m, or greater than 4,000 S/m, or greater than 5,000 S/m, or greaterthan 10,000 S/m, or greater than 20,000 S/m, or greater than 30,000 S/m,or greater than 40,000 S/m, or greater than 50,000 S/m, or greater than60,000 S/m, or greater than 70,000 S/m, or from 500 S/m to 100,000 S/m,or from 500 S/m to 1,000 S/m, or from 500 S/m to 10,000 S/m, or from 500S/m to 20,000 S/m, or from 500 S/m to 100,000 S/m, or from 1000 S/m to10,000 S/m, or from 1,000 S/m to 20,000 S/m, or from 10,000 to 100,000S/m, or from 10,000 S/m to 80,000 S/m, or from 500 S/m to 10,000 S/m. Insome cases, the density of the pellet is approximately 1 g/cm³, orapproximately 1.2 g/cm³, or approximately 1.5 g/cm³, or approximately 2g/cm³, or approximately 2.2 g/cm³, or approximately 2.5 g/cm³, orapproximately 3 g/cm³. Additionally, tests have been performed in whichcompressed pellets of the carbon aggregate materials have been formedwith compressions of 2,000 psi and 12,000 psi and with annealingtemperatures of 800° C. and 1,000° C. The higher compression and/or thehigher annealing temperatures generally result in pellets with a higherdegree of electrical conductivity, including in the range of 12,410.0S/m to 13,173.3 S/m.

High Purity Carbon Allotropes Produced Using Thermal Processing Systems

The carbon nanoparticles and aggregates described herein can be producedusing thermal reactors and methods. Further details pertaining tothermal reactors and/or methods of use can be found in U.S. Pat. No.9,862,602, issued Jan. 9, 2018, entitled “CRACKING OF A PROCESS GAS”,which is hereby incorporated by reference in its entirety. Additionally,carbon-containing and/or hydrocarbon precursors (referring to at leastmethane, ethane, propane, butane, and natural gas) can be used with thethermal reactors to produce the carbon nanoparticles and the carbonaggregates described herein.

The carbon nanoparticles and aggregates described herein are producedusing the thermal reactors with gas flow rates from 1 slm to 10 slm, orfrom 0.1 slm to 20 slm, or from 1 slm to 5 slm, or from 5 slm to 10 slm,or greater than 1 slm, or greater than 5 slm. The carbon nanoparticlesand aggregates described herein are produced using the thermal reactorswith gas resonance times from 0.1 seconds (s) to 30 s, or from 0.1 s to10 s, or from 1 s to 10 s, or from 1 s to 5 s, from 5 s to 10 s, orgreater than 0.1 seconds, or greater than 1 s, or greater than 5 s, orless than 30 s.

The carbon nanoparticles and aggregates described herein can be producedusing the thermal reactors with production rates from 10 g/hr to 200g/hr, or from 30 g/hr to 200 g/hr, or from 30 g/hr to 100 g/hr, or from30 g/hr to 60 g/hr, or from 10 g/hr to 100 g/hr, or greater than 10g/hr, or greater than 30 g/hr, or greater than 100 g/hr.

Thermal reactors (or other cracking apparatuses) and thermal reactormethods (or other cracking methods) can be used for refining,pyrolizing, dissociating or cracking feedstock process gases into itsconstituents to produce the carbon nanoparticles and the carbonaggregates described herein, as well as other solid and/or gaseousproducts (such as, hydrogen gas and/or lower order hydrocarbon gases).The feedstock process gases generally include, for example, hydrogen gas(H²), carbon dioxide (CO²), C¹ to C¹⁰ hydrocarbons, aromatichydrocarbons, and/or other hydrocarbon gases such as natural gas,methane, ethane, propane, butane, isobutane, saturated/unsaturatedhydrocarbon gases, ethene, propene, etc., and mixtures thereof. Thecarbon nanoparticles and the carbon aggregates can include, for example,multi-walled spherical fullerenes (MWSFs), connected MWSFs, carbonnanospheres, graphene, graphite, highly ordered pyrolytic graphite,single-walled nanotubes, multi-walled nanotubes, other solid carbonproducts, and/or the carbon nanoparticles and the carbon aggregatesdescribed herein.

Methods for producing the carbon nanoparticles and the carbon aggregatesdescribed herein can include thermal cracking methods that use, forexample, an elongated longitudinal heating element optionally enclosedwithin an elongated casing, housing or body of a thermal crackingapparatus. The body can include, for example, one or more tubes or otherappropriate enclosures made of stainless steel, titanium, graphite,quartz, or the like. The body of the thermal cracking apparatus isgenerally cylindrical in shape with a central elongate longitudinal axisarranged vertically and a feedstock process gas inlet at or near a topof the body. The feedstock process gas can flow longitudinally downthrough the body or a portion thereof. In the vertical configuration,both gas flow and gravity assist in the removal of the solid productsfrom the body of the thermal cracking apparatus.

The heating element can include any one or more of a heating lamp, oneor more resistive wires or filaments (or twisted wires), metalfilaments, metallic strips or rods, and/or other appropriate thermalradical generators or elements that can be heated to a specifictemperature (such a, a molecular cracking temperature) sufficient tothermally crack molecules of the feedstock process gas. The heatingelement can be disposed, located or arranged to extend centrally withinthe body of the thermal cracking apparatus along the centrallongitudinal axis thereof. In configurations having only one heatingelement can include it placed at or concentric with the centrallongitudinal axis; alternatively, for configurations having multipleheating elements can include them spaced or offset generallysymmetrically or concentrically at locations near and around andparallel to the central longitudinal axis.

Thermal cracking to produce the carbon nanoparticles and aggregatesdescribed herein can be achieved by flowing the feedstock process gasover, or in contact with, or within the vicinity of, the heating elementwithin a longitudinal elongated reaction zone generated by heat from theheating element and defined by and contained inside the body of thethermal cracking apparatus to heat the feedstock process gas to or at aspecific molecular cracking temperature.

The reaction zone can be considered to be the region surrounding theheating element and close enough to the heating element for thefeedstock process gas to receive sufficient heat to thermally crack themolecules thereof. The reaction zone is thus generally axially alignedor concentric with the central longitudinal axis of the body. Thethermal cracking is performed under a specific pressure. The feedstockprocess gas is circulated around or across the outside surface of acontainer of the reaction zone or a heating chamber to cool thecontainer or chamber and preheat the feedstock process gas beforeflowing the feedstock process gas into the reaction zone.

The carbon nanoparticles and aggregates described herein and/or hydrogengas are produced without the use of catalysts. Accordingly, the processcan be entirely catalyst free.

Disclosed methods and systems can advantageously be rapidly scaled up orscaled down for different production levels as may be desired, such asbeing scalable to provide a standalone hydrogen and/or carbonnanoparticle producing station, a hydrocarbon source, or a fuel cellstation, to provide higher capacity systems, such as, for a refineryand/or the like.

A thermal cracking apparatus for cracking a feedstock process gas toproduce the carbon nanoparticles and aggregates described herein includea body, a feedstock process gas inlet, and an elongated heating element.The body has an inner volume with a longitudinal axis. The inner volumehas a reaction zone concentric with the longitudinal axis. A feedstockprocess gas can be flowed into the inner volume through the feedstockprocess gas inlet during thermal cracking operations. The elongatedheating element can be disposed within the inner volume along thelongitudinal axis and is surrounded by the reaction zone. During thethermal cracking operations, the elongated heating element is heated byelectrical power to a molecular cracking temperature to generate thereaction zone, the feedstock process gas is heated by heat from theelongated heating element, and the heat thermally cracks molecules ofthe feedstock process gas that are within the reaction zone intoconstituents of the molecules.

A method for cracking a feedstock process gas to produce the carbonnanoparticles and aggregates described herein can include at least anyone or more of the following: (1) providing a thermal cracking apparatushaving an inner volume that has a longitudinal axis and an elongatedheating element disposed within the inner volume along the longitudinalaxis; (2) heating the elongated heating element by electrical power to amolecular cracking temperature to generate a longitudinal elongatedreaction zone within the inner volume; (3) flowing a feedstock processgas into the inner volume and through the longitudinal elongatedreaction zone (such as, wherein the feedstock process gas is heated byheat from the elongated heating element); and (4) thermally crackingmolecules of the feedstock process gas within the longitudinal elongatedreaction zone into constituents thereof (such as, hydrogen gas and oneor more solid products) as the feedstock process gas flows through thelongitudinal elongated reaction zone.

The feedstock process gas used to produce the carbon nanoparticles andaggregates described herein can include a hydrocarbon gas. The resultsof cracking can, in turn, further include hydrogen in gaseous form (suchas, H²) and various forms of the carbon nanoparticles and aggregatesdescribed herein. The carbon nanoparticles and aggregates include two ormore MWSFs and layers of graphene coating the MWSFs, and/or connectedMWSFs and layers of graphene coating the connected MWSFs. The feedstockprocess gas is preheated (such as, to 100° C. to 500° C.) by flowing thefeedstock process gas through a gas preheating region between a heatingchamber and a shell of the thermal cracking apparatus before flowing thefeedstock process gas into the inner volume. A gas having nanoparticlestherein is flowed into the inner volume and through the longitudinalelongated reaction zone to mix with the feedstock process gas, to form acoating of a solid product (such as, layers of graphene) around thenanoparticles.

Post-Processing High Purity Structured Carbons

The carbon nanoparticles and aggregates containing multi-walledspherical fullerenes (MWSFs) or connected MWSFs described herein can beproduced and collected without requiring the completion of anypost-processing treatments or operations. Alternatively, somepost-processing can be performed on one or more of the presentlydisclosed MWSFs. Some examples of post-processing involved in making andusing resonant materials include mechanical processing such as ballmilling, grinding, attrition milling, micro fluidizing, and othertechniques to reduce the particle size without damaging the MWSFs. Somefurther examples of post-processing include exfoliation processes(referring to the complete separation of layers of carbon-containingmaterial, such as the creation or extraction of layers of graphene fromgraphite, etc.) including sheer mixing, chemical etching, oxidizing(such as the Hummer method), thermal annealing, doping by addingelements during annealing (such as sulfur and/or nitrogen), steaming,filtering, and lyophilization, among others. Some examples ofpost-processing include sintering processes such as spark plasmasintering (SPS), direct current sintering, microwave sintering, andultraviolet (UV) sintering, which can be conducted at high pressure andtemperature in an inert gas. Multiple post-processing methods can beused together or in a series. The post-processing producesfunctionalized carbon nanoparticles or aggregates containingmulti-walled spherical fullerenes (MWSFs) or connected MWSFs.

Materials can be mixed together in different combinations, quantitiesand/or ratios. Different carbon nanoparticles and aggregates containingMWSFs or connected MWSFs described herein can be mixed together prior toone or more post-processing operations, if any at all. For example,different carbon nanoparticles and aggregates containing MWSFs orconnected MWSFs with different properties (such as, different sizes,different compositions, different purities, from different processingruns, etc.) can be mixed together. The carbon nanoparticles andaggregates containing MWSFs or connected MWSFs described herein can bemixed with graphene to change the ratio of the connected MWSFs tographene in the mixture. Different carbon nanoparticles and aggregatescontaining MWSFs or connected MWSFs described herein can be mixedtogether after post-processing. Different carbon nanoparticles andaggregates containing MWSFs or connected MWSFs with different propertiesand/or different post-processing methods (such as, different sizes,different compositions, different functionality, different surfaceproperties, different surface areas) can be mixed together in anyquantity, ratio and/or combination.

The carbon nanoparticles and aggregates described herein are producedand collected, and subsequently processed by mechanical grinding,milling, and/or exfoliating. The processing (such as, by mechanicalgrinding, milling, exfoliating, etc.) can reduce the average size of theparticles. The processing (such as, by mechanical grinding, milling,exfoliating, etc.) increases the average surface area of the particles.The processing by mechanical grinding, milling and/or exfoliation shearsoff some fraction of the carbon layers, producing sheets of graphitemixed with the carbon nanoparticles.

The mechanical grinding or milling is performed using a ball mill, aplanetary mill, a rod mill, a shear mixer, a high-shear granulator, anautogenous mill, or other types of machining used to break solidmaterials into smaller pieces by grinding, crushing or cutting. Themechanical grinding, milling and/or exfoliating is performed wet or dry.The mechanical grinding is performed by grinding for some period oftime, then idling for some period of time, and repeating the grindingand idling for a number of cycles. The grinding period is from 1 minute(min) to 20 mins, or from 1 min to 10 mins, or from 3 mins to 8 mins, orapproximately 3 mins, or approximately 8 mins. The idling period is from1 min to 10 mins, or approximately 5 mins, or approximately 6 mins. Thenumber of grinding and idling cycles is from 1 min to 100 mins, or from5 mins to 100 mins, or from 10 mins to 100 mins, or from 5 mins to 10mins, or from 5 mins to 20 mins. The total amount of time of grindingand idling is from 10 mins to 1,200 mins, or from 10 mins to 600 mins,or from 10 mins to 240 mins, or from 10 mins to 120 mins, or from 100mins to 90 mins, or from 10 mins to 60 mins, or approximately 90 mins,or approximately mins minutes.

The grinding steps in the cycle are performed by rotating a mill in onedirection for a first cycle (such as, clockwise), and then rotating amill in the opposite direction (such as, counterclockwise) for the nextcycle. The mechanical grinding or milling is performed using a ballmill, and the grinding steps are performed using a rotation speed from100 to 1000 rpm, or from 100 to 500 rpm, or approximately 400 rpm. Themechanical grinding or milling is performed using a ball mill that usesa milling media with a diameter from 0.1 mm to 20 mm, or from 0.1 mm to10 mm, or from 1 mm to 10 mm, or approximately 0.1 mm, or approximately1 mm, or approximately 10 mm. The mechanical grinding or milling isperformed using a ball mill that uses a milling media composed of metalsuch as steel, an oxide such as zirconium oxide (zirconia), yttriastabilized zirconium oxide, silica, alumina, magnesium oxide, or otherhard materials such as silicon carbide or tungsten carbide.

The carbon nanoparticles and aggregates described herein are producedand collected, and subsequently processed using elevated temperaturessuch as thermal annealing or sintering. The processing using elevatedtemperatures is done in an inert environment such as nitrogen or argon.The processing using elevated temperatures is done at atmosphericpressure, or under vacuum, or at low pressure. The processing usingelevated temperatures is done at a temperature from 500° C. to 2,500°C., or from 500° C. to 1,500° C., or from 800° C. to 1,500° C., or from800° C. to 1,200° C., or from 800° C. to 1,000° C., or from 2,000° C. to2,400° C., or approximately 8,00° C., or approximately 1,000° C., orapproximately 1,500° C., or approximately 2,000° C., or approximately2,400° C.

The carbon nanoparticles and aggregates described herein are producedand collected, and subsequently, in post processing operations,additional elements or compounds are added to the carbon nanoparticles,thereby incorporating the unique properties of the carbon nanoparticlesand aggregates into other mixtures of materials.

Either before or after post-processing, the carbon nanoparticles andaggregates described herein are added to solids, liquids or slurries ofother elements or compounds to form additional mixtures of materialsincorporating the unique properties of the carbon nanoparticles andaggregates. The carbon nanoparticles and aggregates described herein aremixed with other solid particles, polymers or other materials.

Either before or after post-processing, the carbon nanoparticles andaggregates described herein are used in various applications beyondapplications pertaining to making and using resonant materials. Suchapplications including but not limited to transportation applications(such as, automobile and truck tires, couplings, mounts, elastomeric“o”-rings, hoses, sealants, grommets, etc.) and industrial applications(such as, rubber additives, functionalized additives for polymericmaterials, additives for epoxies, etc.).

FIGS. 22A and 22B show transmission electron microscope (TEM) images ofas-synthesized carbon nanoparticles. The carbon nanoparticles of FIG.22A (at a first magnification) and FIG. 22B (at a second magnification)contain connected multi-walled spherical fullerenes (MWSFs) withgraphene layers that coat the connected MWSFs. The ratio of MWSF tographene allotropes in this example is approximately 80% due to therelatively short resonance times. The MWSFs in FIG. 22B areapproximately 5 nm to 10 nm in diameter, and the diameter can be from 5nm to 500 nm using the conditions described above. The average diameteracross the MWSFs is in a range from 5 nm to 500 nm, or from 5 nm to 250nm, or from 5 nm to 100 nm, or from 5 nm to 50 nm, or from 10 nm to 500nm, or from 10 nm to 250 nm, or from 10 nm to 100 nm, or from 10 nm to50 nm, or from 40 nm to 500 nm, or from 40 nm to 250 nm, or from 40 nmto 100 nm, or from 50 nm to 500 nm, or from 50 nm to 250 nm, or from 50nm to 100 nm. No catalyst was used in this process, and therefore, thereis no central seed containing contaminants. The aggregate particlesproduced in this example had a particle size of approximately 10 μm to100 μm, or approximately 10 μm to 500 μm.

FIG. 22C shows the Raman spectrum of the as-synthesized aggregates inthis example taken with 532 nm incident light. The I_(D)/I_(G) for theaggregates produced in this example is from approximately 0.99 to 1.03,indicating that the aggregates were composed of carbon allotropes with ahigh degree of order.

FIG. 22D and FIG. 22E show example TEM images of the carbonnanoparticles after size reduction by grinding in a ball mill. The ballmilling was performed in cycles with a 3-minute (min) counter-clockwisegrinding operation, followed by a 6 min idle operation, followed by a3-min clockwise grinding operation, followed by a 6-min idle operation.The grinding operations were performed using a rotation speed of 400rpm. The milling media was zirconia and ranged in size from 0.1 mm to 10mm. The total size reduction processing time was from 60 mins to 120mins. After size reduction, the aggregate particles produced in thisexample had a particle size of approximately 1 μm to 5 μm. The carbonnanoparticles after size reduction are connected MWSFs with layers ofgraphene coating the connected MWSFs.

FIG. 22F shows a Raman spectrum from these aggregates after sizereduction taken with a 532 nm incident light. The I_(D)/I_(G) for theaggregate particles in this example after size reduction isapproximately 1.04. Additionally, the particles after size reduction hada Brunauer, Emmett and Teller (BET) specific surface area ofapproximately 40 m²/g to 50 m²/g.

The purity of the aggregates produced in this sample were measured usingmass spectrometry and x-ray fluorescence (XRF) spectroscopy. The ratioof carbon to other elements, except for hydrogen, measured in 16different batches was from 99.86% to 99.98%, with an average of 99.94%carbon.

In this example, carbon nanoparticles were generated using a thermalhot-wire processing system. The precursor material was methane, whichwas flowed from 1 slm to 5 slm. With these flow rates and the toolgeometry, the resonance time of the gas in the reaction chamber was fromapproximately 20 second to 30 seconds, and the carbon particleproduction rate was from approximately 20 g/hr.

Further details pertaining to such a processing system can be found inthe previously mentioned U.S. Pat. No. 9,862,602, titled “CRACKING OF APROCESS GAS.”

EXAMPLES Example 1

FIG. 22G (shown enlarged as FIG. 15), FIG. 22H (shown enlarged as FIG.16) and FIG. 22I (shown enlarged as FIG. 17) show TEM images ofas-synthesized carbon nanoparticles of this example. The carbonnanoparticles contain connected multi-walled spherical fullerenes(MWSFs) with layers of graphene coating the connected MWSFs. The ratioof multi-walled fullerenes to graphene allotropes in this example isapproximately 30% due to the relatively long resonance times allowingthicker, or more, layers of graphene to coat the MWSFs. No catalyst wasused in this process, and therefore, there is no central seed containingcontaminants. The as-synthesized aggregate particles produced in thisexample had particle sizes of approximately 10 μm to 500 μm. FIG. 22Jshows a Raman spectrum from the aggregates of this example. The Ramansignature of the as-synthesized particles in this example is indicativeof the thicker graphene layers which coat the MWSFs in theas-synthesized material. Additionally, the as-synthesized particles hada Brunauer, Emmett and Teller (BET) specific surface area ofapproximately 90 m²/g to 100 m²/g.

Example 2

FIG. 22K and FIG. 22L show TEM images of the carbon nanoparticles ofthis example. Specifically, the images depict the carbon nanoparticlesafter performance of size reduction by grinding in a ball mill. The sizereduction process conditions were the same as those described aspertains to the foregoing FIG. 22G through FIG. 22J. After sizereduction, the aggregate particles produced in this example had aparticle size of approximately 1 μm to 5 μm. The TEM images show thatthe connected MWSFs that were buried in the graphene coating can beobserved after size reduction. FIG. 22M shows a Raman spectrum from theaggregates of this example after size reduction taken with 532 nmincident light. The I_(D)/I_(G) for the aggregate particles in thisexample after size reduction is approximately 1, indicating that theconnected MWSFs that were buried in the graphene coating as-synthesizedhad become detectable in Raman after size reduction, and were wellordered. The particles after size reduction had a Brunauer, Emmett andTeller (BET) specific surface area of approximately 90 m²/g to 100 m²/g.

Example 3

FIG. 22n is a scanning electron microscope (SEM) image of carbonaggregates showing the graphite and graphene allotropes at a firstmagnification. FIG. 22o is a SEM image of carbon aggregates showing thegraphite and graphene allotropes at a second magnification. The layeredgraphene is clearly shown within the distortion (wrinkles) of thecarbon. The 3D structure of the carbon allotropes is also visible.

The particle size distribution of the carbon particles of FIG. 22N andFIG. 22O is shown in FIG. 22P. The mass basis cumulative particle sizedistribution 406 corresponds to the left y-axis in the graph (Q³(x)[%]). The histogram of the mass particle size distribution 408corresponds to the right axis in the graph (dQ³(x) [%]). The medianparticle size is approximately 33 μm. The 10th percentile particle sizeis approximately 9 μm, and the 90th percentile particle size isapproximately 103 μm. The mass density of the particles is approximately10 g/L.

Example 4

The particle size distribution of the carbon particles captured from amultiple-stage reactor is shown in FIG. 22Q. The mass basis cumulativeparticle size distribution 414 corresponds to the left y-axis in thegraph (Q³(x) [%]). The histogram of the mass particle size distribution416 corresponds to the right axis in the graph (dQ³(x) [%]). The medianparticle size captured is approximately 11 μm. The 10th percentileparticle size is approximately 3.5 μm, and the 90th percentile particlesize is approximately 21 μm. The graph in FIG. 22Q also shows the numberbasis cumulative particle size distribution 418 corresponding to theleft y-axis in the graph (Q° (x) [%]). The median particle size bynumber basis is from approximately 0.1 μm to approximately 0.2 μm. Themass density of the particles collected is approximately 22 g/L.

Returning to the discussion of FIG. 22P, the graph also shows a secondset of example results. Specifically, in this example, the particleswere size-reduced by mechanical grinding, and then the size-reducedparticles were processed using a cyclone separator. The mass basiscumulative particle size distribution 410 of the size-reduced carbonparticles captured in this example corresponds to the left y-axis in thegraph (Q³(x) [%]). The histogram of the mass basis particle sizedistribution 412 corresponds to the right axis in the graph (dQ³(x)[%]). The median particle size of the size-reduced carbon particlescaptured in this example is approximately 6 μm. The 10th percentileparticle size is from 1 μm to 2 μm, and the 90th percentile particlesize is from 10 μm to 20 μm.

Further details pertaining to making and using cyclone separators can befound in U.S. patent application Ser. No. 15/725,928, filed Oct. 5,2017, titled “MICROWAVE REACTOR SYSTEM WITH GAS-SOLIDS SEPARATION”,which is hereby incorporated by reference in its entirety.

High Purity Carbon Allotropes Produced using Microwave Reactor Systems

In some cases, carbon particles and aggregates containing graphite,graphene and amorphous carbon can be generated using a microwave plasmareactor system using a precursor material that contains methane, orcontains isopropyl alcohol (IPA), or contains ethanol, or contains acondensed hydrocarbon (such as, hexane). In some other examples, thecarbon-containing precursors are optionally mixed with a supply gas(such as, argon). The particles produced in this example containedgraphite, graphene, amorphous carbon and no seed particles. Theparticles in this example had a ratio of carbon to other elements (otherthan hydrogen) of approximately 99.5% or greater.

In one particular example, a hydrocarbon was the input material for themicrowave plasma reactor, and the separated outputs of the reactorcomprised hydrogen gas and carbon particles containing graphite,graphene and amorphous carbon. The carbon particles were separated fromthe hydrogen gas in a multi-stage gas-solid separation system. Thesolids loading of the separated outputs from the reactor was from 0.001g/L to 2.5 g/L.

Example 5

FIG. 22R, FIG. 22S, and FIG. 22T are TEM images of as-synthesized carbonnanoparticles. The images show examples of graphite, graphene andamorphous carbon allotropes. The layers of graphene and other carbonmaterials can be clearly seen in the images.

The particle size distribution of the carbon particles captured is shownin FIG. 22U. The mass basis cumulative particle size distribution 420corresponds to the left y-axis in the graph (Q³(x) [%]). The histogramof the mass particle size distribution 422 corresponds to the right axisin the graph (dQ³(x) [%]). The median particle size captured in thecyclone separator in this example was approximately 14 μm. The 10thpercentile particle size was approximately 5 μm, and the 90th percentileparticle size was approximately 28 μm. The graph in FIG. 22U also showsthe number basis cumulative particle size distribution 424 correspondingto the left y-axis in the graph (Q° (x) [%]). The median particle sizeby number basis in this example was from approximately 0.1 μm toapproximately 0.2 μm.

Example 6

FIG. 22V, FIG. 22W, and FIG. 22X, and 22X are images that showthree-dimensional carbon-containing structures that are grown onto otherthree-dimensional structures. FIG. 22V is a 100× magnification ofthree-dimensional carbon structures grown onto carbon fibers, whereasFIG. 22W is a 200× magnification of three-dimensional carbon structuresgrown onto carbon fibers. FIG. 22X is a 1601× magnification ofthree-dimensional carbon structures grown onto carbon fibers. Thethree-dimensional carbon growth over the fiber surface is shown. FIG.22Y is a 10000× magnification of three-dimensional carbon structuresgrown onto carbon fibers. The image depicts growth onto the basal planeas well as onto edge planes.

More specifically, FIGS. 22V-22Y show example SEM images of 3D carbonmaterials grown onto fibers using plasma energy from a microwave plasmareactor as well as thermal energy from a thermal reactor. FIG. 22V showsan SEM image of intersecting fiber 431 and fiber 432 with 3D carbonmaterial 430 grown on the surface of the fibers. FIG. 22W is a highermagnification image (the scale bar is 300 μm compared to 500 μm for FIG.22V) showing the 3D carbon material 430 on the fiber 432. FIG. 22X is afurther magnified view (scale bar is 40 μm) showing the 3D carbonmaterial 430 on fiber surface 435, where the 3D nature of the carbonmaterial 430 can be clearly seen. FIG. 22Y shows a close-up view (scalebar is 500 nm) of the carbon alone, showing interconnection betweenbasal planes of the fiber 432 and edge planes 434 of numeroussub-particles of the 3D carbon material grown on the fiber. FIGS.22V-22Y demonstrate the ability to grow 3D carbon on a 3D fiberstructure, such as 3D carbon growth grown on a 3D carbon fiber.

3D carbon growth on fibers can be achieved by introducing a plurality offibers into the microwave plasma reactor and using plasma in themicrowave reactor to etch the fibers. The etching creates nucleationsites such that when carbon particles and sub-particles are created byhydrocarbon disassociation in the reactor, growth of 3D carbonstructures is initiated at these nucleation sites. The direct growth ofthe 3D carbon structures on the fibers, which themselves arethree-dimensional in nature, provides a highly integrated, 3D structurewith pores into which resin can permeate. This 3D reinforcement matrix(including the 3D carbon structures integrated with high aspect ratioreinforcing fibers) for a resin composite results in enhanced materialproperties, such as tensile strength and shear, compared to compositeswith conventional fibers that have smooth surfaces and which smoothsurfaces typically delaminate from the resin matrix.

Functionalization of exposed Carbon Surfaces

Carbon materials, such as any one or more of the 3D carbon materialsdescribed herein, can have one or more exposed surfaces prepared forfunctionalization, such as that to promote adhesion and/or add elementssuch as oxygen, nitrogen, carbon, silicon, or hardening agents.Functionalization refers to the addition of functional groups to acompound by chemical synthesis. In materials science, functionalizationcan be employed to achieve desired surface properties; for instance,functional groups can also be used to covalently link functionalmolecules to the surfaces of chemical devices. The carbon materials canbe functionalized in-situ—that is, on site within the same reactor inwhich the carbon materials are produced. The carbon materials can befunctionalized in post-processing. For example, the surfaces offullerenes or graphene can be functionalized with oxygen- ornitrogen-containing species which form bonds with polymers of the resinmatrix, thus improving adhesion and providing strong binding to enhancethe strength of composites.

Functionalizing surface treatments can be performed on any one or moreof the disclosed carbon-based materials (such as, CNTs, CNO, graphene,3D carbon materials such as 3D graphene) utilizing plasma reactors (suchas, microwave plasma reactors) described herein. Such treatments caninclude in-situ surface treatment during creation of carbon materialsthat can be combined with a binder or polymer in a composite material,or surface treatment after creation of the carbon materials while thecarbon materials are still within the reactor.

Some of the foregoing embodiments include resonators that include aplurality of three-dimensional (3D) aggregates formed ofcarbon-containing material that is embedded within a ply or plies oftire. However, some embodiments include resonators that are printed orotherwise disposed on an inner surface of a tire (e.g., on an innerliner of the tire). Some of such embodiments are shown and discussed aspertains to FIG. 23.

FIG. 23 is presented to illustrate use of split ring resonators (SRRs)as resonance devices that contribute to the ensemble phenomenon arisingfrom different proximally-present resonator types. The figure shows theinner surface 2301 of a tire, where the inner surface has two split ringresonators (e.g., split ring resonator 2303A and split ring resonator2303B), each of which split ring resonator forms a circuit configuration1902 that can be tuned to attenuate a signal at a particular frequencyand/or to attenuate within a particular range of frequencies. In thisembodiment, circuit configuration 1902 is shown as a geometric patternthat corresponds to a substantially-circular split ring resonator;however, alternative circuit configurations can have different geometricpatterns (e.g., cylinders, ellipses, rectangles, ovals, squares, etc.),and as such, any conceivable geometric configuration is possible.Variations of the geometric configurations can be selected based on theimpact on resonation capabilities of the geometric pattern. Inparticular, and as shown, the geometric pattern can compriseself-assembled carbon-based particles having various agglomerationpatterns (e.g., agglomeration pattern 2106, agglomeration pattern 2108,and agglomeration pattern 2110), any one or more of which can constitutea concentrated region 2104 that can impact the resonation performance ofmaterials within which carbon-based microstructures are incorporated. Anagglomeration pattern and/or a series of agglomeration patterns may alsoimpact the resonation performance of materials within which carbon-basedmicrostructures are incorporated.

In various configurations the carbon-based microstructures are formed,at least in part by graphene. In this context, graphene refers to anallotrope of carbon in the form of a single layer of atoms in atwo-dimensional hexagonal lattice in which one atom forms each vertex.Co-location and/or juxtaposition of multiple of such hexagonal latticesinto more complex structures introduces further resonance effects. Forexample, juxtaposition 2302 of two sheets or platelets of graphene mayresonate between themselves at a frequency that is dependent on thelength, width, spacing, thickness, shape of the spacing, and/or otherphysical characteristics of the sheets or platelets and/or theirrelative juxtaposition to each other.

Ensemble Effect

Table 1 depicts one possible chord of attenuations arising from theensemble effect. As shown in the table, each of the structures has adifferent resonant frequency domain that corresponds to its scaledesignation.

TABLE 1 Ensemble effect examples Structure Scale Designation ResonantFrequency Domain Printed Pattern (e.g., split Macro-scale Lower GHz ringresonator geometry) Agglomeration pattern Meso-scale Higher GHzJuxtaposition of graphene Micro-scale Very high GHz sheets or plateletsMolecule Nano-scale THz

Any number of different split ring resonators can be printed onto asurface of a tire. Moreover, any number of different sizes of split ringresonators can be printed onto any of the surfaces of a tire. The choiceof materials and/or the size and/or other structural or dimensionalcharacteristics of a particular split ring resonator can be used tocontrol the resonation frequency of that particular resonator splitring. A series of differently-sized split ring resonators can be printedsuch that the pattern corresponds to a digitally encoded value.Stimulating the series of differently-sized split ring resonators withvia electromagnetic signal communication, for example, sweeping througha range from 8 GHz to 9 GHz or similar, and measuring the attenuationresponse through a range of the return leads to a recognizable encodedserial number. Many different encoding schemes are possible, and assuch, the non-limiting example of Table 2 is merely for illustration.

TABLE 2 Example encoding scheme Size (outer diameter) 1 mm 2 mm 2.5 mm 3mm 4 mm 5 mm 6 mm 7 mm Bit Assignment 8 7 6 5 4 3 2 1 Calibrated 8.8908.690 8.655 8.570 8.470 8.380 8.350 8.275 Attenuation Point (GHz)Encoded 6E Present Present Present Present Present SRR pattern Encoded6E 0 1 1 0 1 1 1 0 bit pattern Encoded 4E Present Present PresentPresent SRR pattern Encoded 4E 0 1 0 0 1 1 1 0 bit pattern Encoded E1Present Present Present Present SRR pattern Encoded E1 1 1 1 0 0 0 0 1bit pattern

FIG. 24 shows use of split ring resonant structures that are configuredto resonate in a manner that corresponds to an encoded serial number.Such a pattern of split ring resonant structures can be printed on tiresor other elastomers. As shown, the encoded serial number “E1” is shownby the presence of split ring resonators of four different sizes. Thestimulus-response diagram 2400 shows EM stimulus in a range of about 8GHz to about 9 GHz, whereas the response is shown as attenuation in arange from about −8 dB to about −18 dB. Stimulating the series ofdifferent sized split ring resonators with via electromagnetic signalcommunication across the range, and measuring the S-parameters of thereturn across the range, leads to convenient and reliable identificationof that particular printed pattern. It follows then that, if a uniquepattern is printed onto each one of a run of tires, and if the patternis associated with an encoded serial number, then a determination of thespecific tire can be made based on the pattern's response to the EMinterrogation. More specifically, if a unique pattern is printed ontoeach one of a run of tires, and if the pattern is associated with anencoded serial number, then a determination of the specific tire can bemade based on measured S-parameters (e.g., S-parameter ratios thatcorrespond to attenuation) in response to EM interrogation over an EMstimulus in a range corresponding to the encoding scheme. In the exampleof FIG. 24, the attenuations fall in a range from about −8 dB to about−18 dB however, in other measurements the attenuations fall in a rangeof about −1 dB to about −9 dB. In other measurements the attenuationsfall in a range of about −10 dB to about −19 dB. In other measurementsthe attenuations fall in a range of about −20 dB to about −35 dB. Inempirical experimentation, the attenuations are substantiallyindependent of the number of differently-configured resonators that areproximally collocated on a tire surface. More particularly, in someexperimentation, the attenuations are particularly pronounced when theresonators are proximally collocated on a tire surface that is on thetread-side of a steel belt (e.g., in a steel belted radial tire).

Although the foregoing examples as discussed and as depicted in Table 1involve only 8 bits of encoding, more bits can be encoded into a patternmerely by increasing the number of differently-configured resonators.This in turn can lead to reliable cradle-to-grave componentidentification of individual units, even when there are many millions ofunique units in existence at any moment in time.

Other Implementations

The foregoing encoding and printing techniques can be used in tires andother elastomer-containing components. In some cases, printing theresonators is carried out at relatively high temperatures and/or withchemical agents (e.g., catalysts) such that chemical bonds are formedbetween the carbon atoms of the resonators and the elastomers. Thechemical bonds that are formed between the carbon atoms of theresonators and the elastomers contribute to ensemble effect, and assuch, calibration curves may be taken to account for the type and extentof the aforementioned chemical bonds.

The elastomer can contain any one or more types of rubber. Isoprene forexample is a common rubber formulation. Isoprene has its own single C—Cbonds and double bonds between the other molecular elements in theligands. Additional double carbon bonds formed by the high-temperatureprinting of the split ring resonators has the effect of increasedconductivity, which effect can be exploited to form larger, lowerfrequency resonators. Additionally, or alternatively, agglomerations canbe tuned into specific sizes, which would give rise to overtones thatcontribute to the ensemble effect, which in turn results in very highsensitivity given EM interrogation in a tuned range. In some cases, theresponse of the materials to EM interrogation is sufficientlydiscernable such that the age or other aspect of the elastomer's healthcan be determined (e.g., by comparison to one or more calibrationcurves).

More specifically, as elastomers age, the molecular spacing changes andcoupling and/or percolation of energy decreases correspondingly, thusshifting the response frequencies as the conductive localities becomemore and more isolated with respect to adjacent localities. In somecases, attenuation and/or return signal strength will change at specificfrequencies. Such changes can be determined over time, and the changescan be used to construct calibration curves.

The design of tires supports many possible locations for printing of thesplit ring resonators. As examples, split ring resonators can be locatedon any inner surface of a tire, including but not limited to the capply, and/or on or near the steel belts (e.g., on the tread side of asteel belt), and/or on or near a radial ply, and/or on the sidewall,and/or on the bead chafers, and/or on the beads, etc.

Use of the split ring resonator techniques are not limited to onlytires. The techniques can be applied to any elastomer-containingcomponents such belts and hoses. Moreover, the use of the split ringresonator techniques are not limited to only vehicles. That is, sinceconsumables exist in organic powertrain and/or drive train components ina wide range of motive devices (e.g., in industrial mechanical systems),the split ring resonator techniques can be applied to those consumablesas well. Some aspects of wear phenomena are a consequence of friction,heat, heat cycling and corrosion, any of which can result in and/oraccelerate changes in the molecular structure of the materials. Changesin the molecular structure of the materials is detectable under EMinterrogation. More specifically, by calculating a frequency shift, aparticular sample's response (e.g., an aged sample's response) under aparticular EM interrogation regime with respect to a calibration curve,the age or health of the material can be assessed based on the magnitudeof the frequency shift.

FIG. 25 is a top view of two layers, where each layer hosts a split ringresonator. As used herein, split ring resonators (SRRs) consist of apair of concentric rings, disposed on a dielectric substrate, where eachring has slits (e.g., due to a printed pattern). When an array of SRRsis excited by means of a time varying magnetic field, the structurebehaves as an effective medium with negative effective permeability in anarrow band around the SRR resonance point. Many geometries arepossible. One particular geometry involves gaps between concentricrings. Such gaps produce a capacitance which in combination with theinductance inherent in the pair of concentric rings introduces a changein the resonance of the ensemble.

A printable, sheet-oriented, cylinder-type, split ring resonator designcan be built out of any electrically-conducting materials, includingmetals, electrically-conducting non-metals, dielectric materials,semiconducting materials, etc. In addition to tuning based on theselection and/or treatment of electrically-conducting materials, splitring resonators can be tuned by varying the geometry such that theeffective permittivity accordingly tuned. Effective permittivity as afunction of the geometry of a split ring resonator is given in EQ 1.

$\begin{matrix}{\mu_{eff} = {1 - \frac{\frac{\pi\; r^{2}}{a^{2}}}{1 + \frac{2l\;\sigma_{1}i}{{wr}\;\mu_{0}} - \frac{3{lc}_{0}^{2}}{\pi\; w^{2}r^{3}{\ln\left( \frac{2c}{d} \right)}}}}} & {{EQ}.\mspace{14mu} 1}\end{matrix}$

where a is the spacing of the cylinders, ω is the angular frequency, μ0is the permeability of free space, r is the radius, d is the spacing ofthe concentric conducting sheets, 1 is a stacking length, c is thethickness of a ring, and σ is the resistance of unit length of thesheets measured around the circumference.

In some situations, the value of a (e.g., the spacing of the cylindersof a cylindrical split ring resonator) can be made relatively small suchthat the concentric rings absorb EM radiation within a relatively narrowfrequency range. In other situations, the value of a can be maderelatively large such that the concentric rings each absorb EM radiationat frequencies that are separated by a wide range. In some situations,differently-sized SRRs can be disposed on different surfaces of thetire. In some situations, the differently-sized SRRs that are disposedon different surfaces of the tire can be used to take measurements oftire conditions (e.g., temperature, aging, wear, etc.).

In some embodiments, the materials that form the split ring resonatorare composite materials. Each SRR can be configured to any particulardesired tuned response to EM stimulation. At least inasmuch as SRRs aredesigned to mimic the resonance response of atoms (though on a muchlarger scale, and at lower frequencies), the larger scale of SRRs ascompared with atoms allows for more control over the resonance response.Moreover, SRRs are much more responsive than ferromagnetic materialsfound in nature. The pronounced magnetic response of SRRs carries withit a significant advantage over heavier, naturally occurring materials.

In the foregoing specification, the disclosure has been described withreference to specific implementations thereof. It will however beevident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the disclosure.For example, the above-described process flows are described withreference to an ordering of process actions. However, the ordering ofmany of the described process actions may be changed without affectingthe scope or operation of the disclosure. The specification and drawingsare to be regarded in an illustrative sense rather than in a restrictivesense.

What is claimed is:
 1. A tire including a body formed of one or moretire plies, each tire ply comprising: a first split-ring resonator (SRR)including a plurality of first carbon particles configured to uniquelyattenuate an electromagnetic ping based at least in part on aconcentration level of the first carbon particles within the first SRR;and a second SRR adjacent to the first SRR and including a plurality ofsecond carbon particles configured to uniquely attenuate theelectromagnetic ping based at least in part on a concentration level ofthe second carbon particles within the second SRR.
 2. The tire of claim1, wherein the first carbon particles include first aggregates forming afirst porous structure, and the second carbon particles include secondaggregates forming a second porous structure.
 3. The tire of claim 2,wherein the first and second porous structures comprise mesoscalestructuring.
 4. The tire of claim 1, wherein the first SRR and thesecond SRR are printed onto a surface of the tire ply.
 5. The tire ofclaim 1, wherein the first SRR is configured to resonate at a firstfrequency in response to the electromagnetic ping, and the second SRR isconfigured to resonate at a second frequency in response to theelectromagnetic ping, the first frequency different than the secondfrequency.
 6. The tire of claim 5, wherein the first and secondfrequencies form an encoded serial number.
 7. The tire of claim 5,wherein an amplitude of the resonance of the first SRR or the second SRRis indicative of an extent of wear of the tire ply.
 8. The tire of claim1, wherein an amount of the attenuation of the electromagnetic ping bythe first SRR and the second SRR is indicative of an extent of wear ofthe tire ply.
 9. The tire of claim 1, wherein each of the first SRR andthe second SRR has an attenuation point.
 10. The tire of claim 9,wherein the attenuation point of each the first SRR and the second SRRis associated with a frequency response to the electromagnetic ping. 11.The tire of claim 1, wherein each of the first and second carbonparticles is chemically bonded with the tire ply.
 12. The tire of claim1, wherein each of the first SRR and the second SRR has a principaldimension associated with one or more of an S-parameter or a frequencyof the electromagnetic ping.
 13. The tire of claim 1, wherein at leastone of the first SRR or the second SRR has one of an oval shape, anelliptical shape, a rectangular shape, a square shape, a circle shape,or a curved line.
 14. The tire of claim 1, wherein one or more of thefirst SRR or the second SRR comprises a cylindrical SRR.
 15. The tire ofclaim 1, wherein the first SRR and the second SRR are configured as apair of concentric rings.
 16. The tire of claim 15, wherein the firstSRR is positioned outside the second SRR.
 17. The tire of claim 1,wherein the first SRR and the second SRR are disposed within an innerliner of the tire.
 18. The tire of claim 1, wherein the first SRR andthe second SRR are disposed on a treaded side of the tire body.
 19. Thetire of claim 1, wherein each of the first SRR and the second SRR has anegative effective permeability.
 20. The tire of claim 1, wherein eachof the first SRR and the second SRR includes one or more ofelectrically-conducting materials, metals, electrically-conductingnon-metals, dielectric materials, or semiconducting materials.